Effect Of Matrix Ductility On The Performance Of Reinforced

In this paper, a research study is presented focusing on the effect of substituting brittle concrete in conventional reinforced concrete column members with a ductile engineered cementitious composite (ECC). Based on the material properties of ECC, the interaction with structural reinforcement is characterized by compatible deformations of the reinforcement and ECC matrix in the elastic and inelastic deformation regime. This unique composite deformation mechanism has significant implications on the performance of reinforced ECC structural composite members under reversed cyclic loading conditions. Important findings of this study include the extremely ductile response of steel reinforced ECC members at a simultaneous reduction of transverse reinforcement requirements as well as reduced structural damage after experiencing relatively large deformation reversals. Furthermore, the combination of ECC with structural FRP reinforcement results in composite members with an elastic load-deformation response and small residual displacements

What an emergency physician needs to know about acute care of cardiac arrhythmias

The treat of cardiac arrhythmias has been studied extensively in the last decades. There has been a major shift in antiarrhythmia treatment from drugs to interventional electrophysiological procedures and implantable devices. Published data indicate that for long-term treatment of arrhythmias, non-pharmacological treatment is more effective than drugs in many patients. Similarly, the overhelming success of radiofrequency catheter ablation of supraventricular tachycardias has almost eliminated the need for chronic drug treatment. Today, catheter ablation plays an increasingly important role in the prevention of atrial fibrillation recurrences. However, in the emergency room or in the intensive care unit, drug treatment remains the gold standard for the treatment of cardiac arrhythmias. Arrhythmias are very common in emergency medicine, occurring in 12% to 20% of all patients in an intensive care unit and there is great need for good diagnostic and therapeutic algorithms to aid the emergency physician dealing with patients suffering from arrhythmia

Resting-state global functional connectivity as a biomarker of cognitive reserve in mild cognitive impairment

Cognitive reserve (CR) shows protective effects in Alzheimer’s disease (AD) and reduces the risk of dementia. Despite the clinical significance of CR, a clinically useful diagnostic biomarker of brain changes underlying CR in AD is not available yet. Our aim was to develop a fully-automated approach applied to fMRI to produce a biomarker associated with CR in subjects at increased risk of AD. We computed resting-state global functional connectivity (GFC), i.e. the average connectivity strength, for each voxel within the cognitive control network, which may sustain CR due to its central role in higher cognitive function. In a training sample including 43 mild cognitive impairment (MCI) subjects and 24 healthy controls (HC), we found that MCI subjects with high CR (> median of years of education, CR+) showed increased frequency of high GFC values compared to MCI-CR- and HC. A summary index capturing such a surplus frequency of high GFC was computed (called GFC reserve (GFC-R) index). GFC-R discriminated MCI-CR+ vs. MCI-CR-, with the area under the ROC = 0.84. Cross-validation in an independently recruited test sample of 23 MCI subjects showed that higher levels of the GFC-R index predicted higher years of education and an alternative questionnaire-based proxy of CR, controlled for memory performance, gray matter of the cognitive control network, white matter hyperintensities, age, and gender. In conclusion, the GFC-R index that captures GFC changes within the cognitive control network provides a biomarker candidate of functional brain changes of CR in patients at increased risk of AD