Cognitive dysfunction in Adult Congenital Heart Disease with different structural complexity

We carried out a cross-sectional study to assess cognitive function in a sample of adult CHD patients, within the Functioning in Adult Congenital Heart Disease study London. The association between cognitive functioning and disease complexity was examined. A total of 310 patients participated in this study. Patients were classified into four structural complexity groups – tetralogy of Fallot, transposition of the great arteries, single ventricle, and simple conditions. Each patient underwent neuropsychological assessment to evaluate cognitive function, including memory and executive function, and completed questionnaires to assess depression and anxiety. Among all, 41% of the sample showed impaired performance (>1.5 SD below the normative mean) on at least three tests of cognitive function compared with established normative data. This was higher than the 8% that was expected in a normal population. The sample exhibited significant deficits in divided attention, motor function, and executive functioning. There was a significant group difference in divided attention (F=5.01, p=0.002) and the mean total composite score (F=5.19, p=0.002) between different structural complexity groups, with the simple group displaying better cognitive function. The results indicate that many adult CHD patients display impaired cognitive function relative to a healthy population, which differs in relation to disease complexity. These findings may have implications for clinical decision making in this group of patients during childhood. Possible mechanisms underlying these deficits and how they may be reduced or prevented are discussed; however, further work is needed to draw conclusive judgements

Arrhythmogenic right ventricular cardiomyopathy/dysplasia

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a heart muscle disease clinically characterized by life-threatening ventricular arrhythmias. Its prevalence has been estimated to vary from 1:2,500 to 1:5,000. ARVC/D is a major cause of sudden death in the young and athletes. The pathology consists of a genetically determined dystrophy of the right ventricular myocardium with fibro-fatty replacement to such an extent that it leads to right ventricular aneurysms. The clinical picture may include: a subclinical phase without symptoms and with ventricular fibrillation being the first presentation; an electrical disorder with palpitations and syncope, due to tachyarrhythmias of right ventricular origin; right ventricular or biventricular pump failure, so severe as to require transplantation. The causative genes encode proteins of mechanical cell junctions (plakoglobin, plakophilin, desmoglein, desmocollin, desmoplakin) and account for intercalated disk remodeling. Familiar occurrence with an autosomal dominant pattern of inheritance and variable penetrance has been proven. Recessive variants associated with palmoplantar keratoderma and woolly hair have been also reported. Clinical diagnosis may be achieved by demonstrating functional and structural alterations of the right ventricle, depolarization and repolarization abnormalities, arrhythmias with the left bundle branch block morphology and fibro-fatty replacement through endomyocardial biopsy. Two dimensional echo, angiography and magnetic resonance are the imaging tools for visualizing structural-functional abnormalities. Electroanatomic mapping is able to detect areas of low voltage corresponding to myocardial atrophy with fibro-fatty replacement. The main differential diagnoses are idiopathic right ventricular outflow tract tachycardia, myocarditis, dialted cardiomyopathy and sarcoidosis. Only palliative therapy is available and consists of antiarrhythmic drugs, catheter ablation and implantable cardioverter defibrillator. Young age, family history of juvenile sudden death, QRS dispersion ≥ 40 ms, T-wave inversion, left ventricular involvement, ventricular tachycardia, syncope and previous cardiac arrest are the major risk factors for adverse prognosis. Preparticipation screening for sport eligibility has been proven to be effective in detecting asymptomatic patients and sport disqualification has been life-saving, substantially declining sudden death in young athletes

Automatic edge identification for accurate analysis of thermographic images of solar panels

This paper proposes a segmentation method to analyze thermographic images of large solar fields with the aim to identify the borders of photovoltaic modules. This kind of analysis allows to correctly attribute possible faults, revealed by thermography, to a well specified solar panel. Moreover, the knowledge of the specific model of solar panel allows to bring the analysis to the single solar cell. This latter feature can help to eliminate some false positive that the mere observation of hot spots might produce

Wireless Sensor for Monitoring of Individual PV Modules

The paper deals with a module-level monitoring and diagnostic system consisting in wireless self-powered sensors installed on individual PV modules and performing real-time measurements of operating voltage and current, open-circuit voltage, and short-circuit current. A disconnection system assures that the PV sensor does not affect the behavior of the string during the measurement phase and allows many benefits like the automatic detection of bypass events. An experimental campaign is performed to prove the reliability and usefulness of the sensor for monitoring of PV plants. The capability to detect faults and to accurately localize malfunctioning modules in a PV string is highlighted

A Power MOS Based Circuit for Controlling the Hot Spot Temperature in Photovoltaic Modules

Localized overtemperature (hot spot) is universally recognized as the main cause of unexpected failure and reliability issues in photovoltaic plants. In fact, the hot spot temperature can be so high to permanently injury the solar panel. Right now, the only countermeasure adopted by solar panel manufacturers is to group solar cells in shorter strings, so that the allowed electrical power in each group is low enough to keep the overtemperature within safe limits. In this paper, a bypass circuit able of controlling power dissipation by modulating the current flowing through the affected solar cell, up to, if applicable, completely cancelling such current. This latter is deviated through a parallel bypass diode (as in standard solar panels), whose possible over heating is in turn prevented by the proper sharing of the current. The correct operation of the circuit is evidenced by means of experiments showing the capability to regulate the overtemperature from zero to the hot spot