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

A Gaussian Sum-Rules Analysis of Scalar Glueballs

Although marginally more complicated than the traditional Laplace sum-rules, Gaussian sum-rules have the advantage of being able to probe excited and ground states with similar sensitivity. Gaussian sum-rule analysis techniques are applied to the problematic scalar glueball channel to determine masses, widths and relative resonance strengths of low-lying scalar glueball states contributing to the hadronic spectral function. A feature of our analysis is the inclusion of instanton contributions to the scalar gluonic correlation function. Compared with the next-to-leading Gaussian sum-rule, the analysis of the lowest-weighted sum-rule (which contains a large scale-independent contribution from the low energy theorem) is shown to be unreliable because of instability under QCD uncertainties. However, the presence of instanton effects leads to approximately consistent mass scales in the lowest weighted and next-lowest weighted sum-rules. The analysis of the next-to-leading sum-rule demonstrates that a single narrow resonance model does not provide an adequate description of the hadronic spectral function. Consequently, we consider a wide variety of phenomenological models which distribute resonance strength over a broad region---some of which lead to excellent agreement between the theoretical prediction and phenomenological models. Including QCD uncertainties, our results indicate that the hadronic contributions to the spectral function stem from a pair of resonances with masses in the range 0.8--1.6 GeV, with the lighter of the two potentially having a large width.Comment: latex2e, 22 pages, 5 figures. Analysis extended in revised versio

Glueball Spectroscopy in a Relativistic Many-Body Approach to Hadron Structure

A comprehensive, relativistic many-body approach to hadron structure is advanced based on the Coulomb gauge QCD Hamiltonian. Our method incorporates standard many-body techniques which render the approximations amenable to systematic improvement. Using BCS variational methods, dynamic chiral symmetry breaking naturally emerges and both quarks and gluons acquire constituent masses. Gluonia are studied both in the valence and in the collective, random phase approximations. Using representative values for the strong coupling constant and string tension, calculated quenched glueball masses are found to be in remarkable agreement with lattice gauge theory.Comment: 12 pages, 1 uuencoded ps figure, RevTe

Calidad de vida tras la implantación de un marcapasos

Describimos un estudio prospectivo para evaluar la calidad de vida relacionada con el estado de salud, mediante el perfil de salud de Nottingham (PSN). y poderla comparar con valoraciones cardiológicas convencionales como la sintomatología y la prueba de esfuerzo, en un grupo de 33 pacientes (65.5 + 2.57 años), antes y después (postimplante, primer y segundo mes) de la implantación de un marcapasos definitivo (A1P). La mejoría clínica tras la implantación, fue mayor en los pacientes que referían haber tenido síncopes (100%), siendo menos marcada en los que referían debilidad (62.5%) y dolor torácico (75%). En los 2 meses de seguimiento hubo 3 hospitalizaciones (10%) por complicaciones del MP (infección de la bolsa, desplazamiento de la sonda auricular y estimulación diafragmática no controlable con reprogramación). A los dos meses de seguimiento el 57% de los pacientes sigue evitando hacer esfuerzos; asimismo, expresaban miedo a fallo del marcapasos 10 pacientes (30%), sin embargo el contacto con los electrodomésticos sólo generaba temor en 2 pacientes (6%). El área de movilidad del PSN se correlacionó con la capacidad de realizar la prueba de esfuerzo (0.371, p < 0.05). A los 2 meses de la implantación del marcapasos hubo una mejoría de la calidad de vida global expresada por/a puntuación total del PSN (14.41 ± 1.7 frente a 9.8 ± 1.0). El análisis por áreas evidenció mejoría generalizada de las áreas: dolor (p < 0.05), movilidad (p < 0.01), aislamiento social (p < 0.01), y reacciones emocionales (p < 0.05). Concluimos que el perfil de salud de Nottingham (PSN) evalúa aceptablemente la mejoría de la salud autopercibida experimentada por nuestros pacientes tras el implante de un marcapasos

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

Sum rule analysis of vector and axial-vector spectral functions with excited states in vacuum

We simultaneously analyze vector and axial-vector spectral functions in vacuum using hadronic models constrained by experimental data and the requirement that Weinberg-type sum rules are satisfied. Upon explicit inclusion of an excited vector state, viz. rho', and the requirement that the perturbative continua are degenerate in vector and axial-vector channels, we deduce the existence of an excited axial-vector resonance state, a1', in order that the Weinberg sum rules are satisfied. The resulting spectral functions are further tested with QCD sum rules.Comment: 11 pages (corrected typos and made paper agree with published version

The sigma and f_0(980) from Ke4 + pi-pi scatterings data

We systematically reconsider, within an improved "analytic K-matrix model", the extraction of the sigma = f_0(600) and f_0(980) masses, widths and hadronic couplings using new Ke4 = K-->pi-pi e nu_e data on pi-pi phase shift below 390 MeV and different sets of pi-pi--> pi-pi / K-K scatterings data from 400 MeV to 1.4 GeV. Our results are summarized in Tables 1, 2 and 5. In units of MeV, the complex poles are: M_sigma=452(12) - i 260(15) and M_f=981(34) -i 18(11), which are comparable with some recent high-precision determinations and with PDG values. Besides some other results, we find: |g_{sigma K+K-}|/|g_{sigma pi+pi-}|=0.37(6) which confirms a sizeable g_{sigma K+K-} coupling found earlier, and which disfavours a large pi-pi molecule or four-quark component of the sigma, while its broad pi-pi width (relative to the one of the rho-meson) cannot be explained within a \bar qq scenario. The narrow pi-pi width of the f_0(980) and the large value: |g_{f K+K-}|/|g_{f pi+pi-}|=2.59(1.34), excludes its pure (\bar uu+\bar dd) content. A significant gluonium component eventually mixed with \bar qq appears to be necessary for evading the previous difficulties.Comment: 9 pages, 3 figures, 6 table

Amphilimus- vs. zotarolimus-eluting stents in patients with diabetes mellitus and coronary artery disease: the SUGAR trial

Aim: Patients with diabetes mellitus are at high risk of adverse events after percutaneous revascularization, with no differences in outcomes between most contemporary drug-eluting stents. The Cre8 EVO stent releases a formulation of sirolimus with an amphiphilic carrier from laser-dug wells, and has shown clinical benefits in diabetes. We aimed to compare Cre8 EVO stents to Resolute Onyx stents (a contemporary polymer-based zotarolimus-eluting stent) in patients with diabetes. Methods and results: We did an investigator-initiated, randomized, controlled, assessor-blinded trial at 23 sites in Spain. Eligible patients had diabetes and required percutaneous coronary intervention. A total of 1175 patients were randomly assigned (1:1) to receive Cre8 EVO or Resolute Onyx stents. The primary endpoint was target-lesion failure, defined as a composite of cardiac death, target-vessel myocardial infarction, and clinically indicated target-lesion revascularization at 1-year follow-up. The trial had a non-inferiority design with a 4% margin for the primary endpoint. A superiority analysis was planned if non-inferiority was confirmed. There were 106 primary events, 42 (7.2%) in the Cre8 EVO group and 64 (10.9%) in the Resolute Onyx group [hazard ratio (HR) 0.65, 95% confidence interval (CI) 0.44 to 0.96; pnon-inferiority <0.001; psuperiority = 0.030]. Among the secondary endpoints, Cre8 EVO stents had significantly lower rate than Resolute Onyx stents of target-vessel failure (7.5% vs 11.1%, HR 0.67, 95% CI 0.46 to 0.99; p = 0.042). Probable or definite stent thrombosis and all-cause death were not significantly different between groups. Conclusions: In patients with diabetes, Cre8 EVO stents were non-inferior to Resolute Onyx stents with regard to target-lesion failure composite outcome. An exploratory analysis for superiority at 1 year suggests that the Cre8 EVO stents might be superior to Resolute Onyx stents with regard to the same outcome

Impact of Diabetes on 10‐Year Outcomes Following ST‐Segment–Elevation Myocardial Infarction: Insights From the EXAMINATION‐EXTEND Trial

BACKGROUND: Long-term outcomes of ST-segment-elevation myocardial infarction in patients with diabetes have been barely investigated. The objective of this analysis from the EXAMINATION-EXTEND (10-Years Follow-Up of the EXAMINATION trial) trial was to compare 10-year outcomes of patients with ST-segment-elevation myocardial infarction with and without diabetes. METHODS AND RESULTS: Of the study population, 258 patients had diabetes and 1240 did not. The primary end point was patient-oriented composite end point of all-cause death, any myocardial infarction, or any revascularization. Secondary end points were the individual components of the primary combined end point, cardiac death, target vessel myocardial infarction, target lesion revascularization, and stent thrombosis. All end points were adjusted for potential confounders. At 10 years, patients with diabetes showed a higher incidence of patient-oriented composite end point compared with those without (46.5% versus 33.0%; adjusted hazard ratio [HR], 1.31 [95% CI, 1.05-1.61]; P=0.016) mainly driven by a higher incidence of any revascularization (24.4% versus 16.6%; adjusted HR, 1.61 [95% CI, 1.19-2.17]; P=0.002). Specifically, patients with diabetes had a higher incidence of any revascularization during the first 5 years of follow-up (20.2% versus 12.8%; adjusted HR, 1.57 [95% CI, 1.13-2.19]; P=0.007) compared with those without diabetes. No statistically significant differences were found with respect to the other end points. CONCLUSIONS: Patients with ST-segment-elevation myocardial infarction who had diabetes had worse clinical outcome at 10 years compared with those without diabetes, mainly driven by a higher incidence of any revascularizations in the first 5 years

The effects of material formulation and manufacturing process on mechanical and thermal properties of epoxy/clay nanocomposites

A holistic study was conducted to investigate the combined effect of three different pre-mixing processes, namely mechanical mixing, ultrasonication and centrifugation, on mechanical and thermal properties of epoxy/clay nanocomposites reinforced with different platelet-like montmorillonite (MMT) clays (Cloisite Na+, Cloisite 10A, Cloisite 15 or Cloisite 93A) at clay contents of 3–10 wt%. Furthermore, the effect of combined pre-mixing processes and material formulation on clay dispersion and corresponding material properties of resulting composites was investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), flexural and Charpy impact tests, Rockwell hardness tests and differential scanning calorimetry (DSC). A high level of clay agglomeration and partially intercalated/exfoliated clay structures were observed regardless of clay type and content. Epoxy/clay nanocomposites demonstrate an overall noticeable improvement of up to 10 % in the glass transition temperature (Tg) compared to that of neat epoxy, which is interpreted by the inclusion of MMT clays acting as rigid fillers to restrict the chain mobility of epoxy matrices. The impact strength of epoxy/clay nanocomposites was also found to increase by up to 24 % with the addition of 3 wt% Cloisite Na+ clays. However, their flexural strength and hardness diminished when compared to those of neat epoxy, arising from several effects including clay agglomeration, widely distributed microvoids and microcracks as well as weak interfacial bonding between clay particles and epoxy matrices, as confirmed from TEM and SEM results. Overall, it is suggested that an improved technique should be used for the combination of pre-mixing processes in order to achieve the optimal manufacturing condition of uniform clay dispersion and minimal void contents