From Poincare to affine invariance: How does the Dirac equation generalize?

A generalization of the Dirac equation to the case of affine symmetry, with SL(4,R) replacing SO(1,3), is considered. A detailed analysis of a Dirac-type Poincare-covariant equation for any spin j is carried out, and the related general interlocking scheme fulfilling all physical requirements is established. Embedding of the corresponding Lorentz fields into infinite-component SL(4,R) fermionic fields, the constraints on the SL(4,R) vector-operator generalizing Dirac's gamma matrices, as well as the minimal coupling to (Metric-)Affine gravity are studied. Finally, a symmetry breaking scenario for SA(4,R) is presented which preserves the Poincare symmetry.Comment: 34 pages, LaTeX2e, 8 figures, revised introduction, typos correcte

Gamma-widths, lifetimes and fluctuations in the nuclear quasi-continuum

Statistical $\gamma$-decay from highly excited states is determined by the nuclear level density (NLD) and the $\gamma$-ray strength function ($\gamma$SF). These average quantities have been measured for several nuclei using the Oslo method. For the first time, we exploit the NLD and $\gamma$SF to evaluate the $\gamma$-width in the energy region below the neutron binding energy, often called the quasi-continuum region. The lifetimes of states in the quasi-continuum are important benchmarks for a theoretical description of nuclear structure and dynamics at high temperature. The lifetimes may also have impact on reaction rates for the rapid neutron-capture process, now demonstrated to take place in neutron star mergers.Comment: CGS16, Shanghai 2017, Proceedings, 5 pages, 3 figure

Case report: Stenosis turned leak … and turned stenosis-complications of paravalvular prosthetic leak closure with a plug device.

Paravalvular leak is one of the most common complications and is among the most important prognostic factors of short- and long-term mortality after transcatheter aortic valve implantation (TAVI). Percutaneous valvular leak repair constitutes a first-line treatment for paravalvular leaks and is associated with high success rates and few serious complications nowadays. To the best of our knowledge, this is the first case where placement of the device through the stenting of the bioprosthesis resulted in creating a new symptomatic stenosis that required surgery. We present a case of a patient with low-flow, low-gradient aortic stenosis treated with transfemoral implantation of a biological aortic prosthesis. One month after the procedure, the patient presented with acute pulmonary oedema and a paravalvular leak was discovered, which was corrected by percutaneous repair with a plug device. Five weeks after the valvular leak repair, the patient was readmitted for heart failure. At this time, a new aortic stenosis and paravalvular leak were diagnosed and the patient was referred for surgery. The new aortic mixed diseased was caused by the positioning of the plug device through the valve's metal stenting, which resulted in a paravalvular leak and pressed against the valve's leaflets, causing valvular stenosis. The patient was referred for surgical replacement and evolved well afterward. This case illustrates a rare complication of a complex procedure, and it highlights the need for multidisciplinary decisions and good cooperation between the cardiology and cardiac surgery teams to develop better criteria in the selection of the appropriate technique for managing paravalvular leaks after TAVI

Effect of time to onset on clinical features and prognosis of post-sternotomy mediastinitis

AbstractIncubation time affects the clinical features and outcome of many nosocomial infections. However, its role in the setting of post-sternotomy mediastinitis (PSM) has not been specifically studied. The present study aimed to evaluate the impact of time to onset of PSM on the clinical presentation and outcomes of patients. Hospital records of 197 patients who developed PSM over a 10-year period and were treated by closed drainage using Redon catheters were reviewed retrospectively. Follow-up was complete for all included patients (median of 19 months); 98 patients developed early-onset PSM (time from initial operation to PSM <14 days) and 99 patients had late-onset PSM (≥14 days). Patients with late-onset PSM had a higher rate of internal thoracic artery harvest and mediastinal re-exploration after initial operation. Patients with early-onset PSM presented more frequently with septic shock. Microbiological findings differed between early- and late-onset PSM by a higher incidence of Enterococcus species in the former and of Staphylococcus aureus in the latter. Overall mortality reached 34% (n = 66). Rates of superinfection, treatment failure, mediastinitis-related death, mortality at 1 year and overall mortality were all significantly higher in patients with early-onset PSM. Multiple regression procedures identified early-onset PSM as a significant and independent risk factor for both 1-year (OR 2.40; 95% CI 1.12-5.11) and overall (OR 2.11; 95% 1.26-3.53) mortality. In conclusion, the results obtained in the present study support the distinction between early- and late-onset PSM with different clinical and pathophysiological features. Early-onset PSM is associated with a significantly higher morbidity and mortality compared to late-onset PSM

The prognostic value of pulmonary artery compliance in cardiogenic shock.

The aim of this study was to evaluate the pathophysiological role and the prognostic significance of pulmonary artery compliance (C &lt;sub&gt;PA&lt;/sub&gt; ), a measure of right ventricular pulsatile afterload, in cardiogenic shock. We retrospectively included 91 consecutive patients with cardiogenic shock due to primary left ventricular failure, monitored with a pulmonary artery catheter within the first 24 h. C &lt;sub&gt;PA&lt;/sub&gt; was calculated as the ratio of stroke volume to pulmonary artery pulse pressure, and we determined whether C &lt;sub&gt;PA&lt;/sub&gt; predicted mortality and whether it performed better than other pulmonary hemodynamic variables. The overall in-hospital mortality in our cohort was 27%. Survivors and nonsurvivors had comparable left ventricular ejection fraction, systolic, diastolic and mean pulmonary artery pressure, transpulmonary gradient, diastolic pressure gradient, and pulmonary vascular resistance at 24 h. In contrast, C &lt;sub&gt;PA&lt;/sub&gt; was the only pulmonary artery variable significantly associated with mortality in univariate and multivariate analyses. Mortality increased from 4.5% at the highest quartile of C &lt;sub&gt;PA&lt;/sub&gt; (3.6-6.5 mL/mmHg) to 43.5% at the lowest quartile (0.7-1.7 mL/mmHg). In 64 patients with a PAC inserted immediately upon admission, we calculated the trend of C &lt;sub&gt;PA&lt;/sub&gt; between admission and 24 h. This trend was positive in survivors (+0.8 ± 1.3 ml/mmHg) but negative in nonsurvivors (-0.1 ± 1.0 mL/mmHg). The lower C &lt;sub&gt;PA&lt;/sub&gt; in nonsurvivors was associated with more severe right ventricular systolic dysfunction. In conclusion, a reduced compliance of the pulmonary artery promotes right ventricular dysfunction and is independently associated with mortality in cardiogenic shock. Future studies should evaluate the impact on pulmonary arterial compliance and right ventricular afterload of therapies used in cardiogenic shock

The First INTEGRAL AGN Catalog

We present the first INTEGRAL AGN catalog, based on observations performed from launch of the mission in October 2002 until January 2004. The catalog includes 42 AGN, of which 10 are Seyfert 1, 17 are Seyfert 2, and 9 are intermediate Seyfert 1.5. The fraction of blazars is rather small with 5 detected objects, and only one galaxy cluster and no star-burst galaxies have been detected so far. A complete subset consists of 32 AGN with a significance limit of 7 sigma in the INTEGRAL/ISGRI 20-40 keV data. Although the sample is not flux limited, the distribution of sources shows a ratio of obscured to unobscured AGN of 1.5 - 2.0, consistent with luminosity dependent unified models for AGN. Only four Compton-thick AGN are found in the sample. Based on the INTEGRAL data presented here, the Seyfert 2 spectra are slightly harder (Gamma = 1.95 +- 0.01) than Seyfert 1.5 (Gamma = 2.10 +- 0.02) and Seyfert 1 (Gamma = 2.11 +- 0.05).Comment: 17 pages, 12 figures, accepted for publication in Ap