QT dispersion in patients with systemic lupus erythematosus: the impact of disease activity

<p>Abstract</p> <p>Background</p> <p>Patients with systemic lupus erythematosus (SLE) have increased cardiovascular morbidity and mortality. Although autopsy studies have documented that the heart is affected in most SLE patients, clinical manifestations occur in less than 10%. QT dispersion is a new parameter that can be used to assess homogeneity of cardiac repolarization and autonomic function. We compared the increase in QT dispersion in SLE patients with high disease activity and mild or moderate disease activity.</p> <p>Methods and Results</p> <p>One hundred twenty-four patients with SLE were enrolled in the study. Complete history and physical exam, ECG, echocardiography, exercise test and SLE disease activity index (SLEDAI) were recorded. Twenty patients were excluded on the basis of our exclusion criteria. The patients were divided to two groups based on SLEDAI: 54 in the high-score group (SLEDAI > 10) and 50 in the low-score group (SLEDAI < 10).</p> <p>QT dispersion was significantly higher in high-score group (58.31 ± 18.66 vs. 47.90 ± 17.41 respectively; <it>P </it>< 0.004). QT dispersion was not significantly higher in patients who had received hydroxychloroquine (54.17 ± 19.36 vs. 50.82 ± 15.96, <it>P </it>= 0.45) or corticosteroids (53.58 ± 19.16 vs. 50.40 + 11.59, <it>P </it>= 0.47). There was a statistically significant correlation between abnormal echocardiographic findings (abnormalities of pericardial effusion, pericarditis, pulmonary hypertension and Libman-Sacks endocarditis) and SLEADI (<it>P </it>< 0.004).</p> <p>Conclusions</p> <p>QT dispersion can be a useful, simple noninvasive method for the early detection of cardiac involvement in SLE patients with active disease. Concerning high chance of cardiac involvement, cardiovascular evaluation for every SLE patient with a SLEDAI higher than 10 may be recommended.</p> <p>Trial registration</p> <p>Clinicaltrial.gov registration <a href="http://www.clinicaltrials.gov/ct2/show/NCT01031797">NCT01031797</a></p

Experimental and numerical analysis of penetration into Kevlar fabric impregnated with shear thickening fluid

This study presents the high-velocity impact performance of a composite material composed of woven Kevlar fabric impregnated with a colloidal shear thickening fluids (STFs). Although the precise role of the STF in the high-velocity defeat, process is not exactly known but it is suspected to be due to the increased frictional interaction between yarns in impregnated fabrics. In order to explore the mechanism of this enhanced energy absorption, high-velocity impact test was conducted on neat, impregnated fabric and also on pure STF without fabric. A finite element model has been carried out to consider the effect of STF impregnation on the ballistic performance. For this purpose, fabric was modeled using LS-DYNA by employing the experimental results of yarn pull-out tests to characterize the frictional behavior of the STF impregnated fabric. The simulation result is a proof that the increased performance for STF impregnated Kevlar fabric is due to the increased friction. </jats:p