A CMOS application-specified-integrated-circuit for 40 GHz high-electron-mobility-transistors automatic biasing.

This paper presents the design and the experimental results of a CMOS Automatic Control System (ACS) for the biasing of High-Electron-Mobility-Transistors (HEMT). The ACS is the first low-power mixed-signal Application-Specified-Integrated-Circuit (ASIC) able to automatically set and regulate the operating point of an off-chip 6 HEMT Low-Noise-Amplifiers (LNAs), hence it composes a two-chip system (the ACS+LNAs) to be used in the Large Scale Polarization Explorer (LSPE) stratospheric balloon for Cosmic Microwave Background (CMB) signal observation. The hereby presented ACS ASIC provides a reliable instrumentation for gradual and very stable LNAs characterization, switching-on, and operating point (<4 mV accuracy). Moreover, it simplifies the electronic instrumentation needed for biasing the LNAs, since it replaces several off-the-shelf and digital programmable device components. The ASIC prototype has been implemented in a CMOS 0.35 µm technology (12 mm2 area occupancy). It operates at 4 kHz clock frequency. The power consumption of one-channel ASIC (biasing one LNA) is 3.6 mW, whereas 30 mW are consumed by a single LNA device.

MRI evaluation of myocardial viability.

Cardiac magnetic resonance imaging (MRI) has become an accurate noninvasive imaging procedure for the study of postischaemic residual cardiac function, thanks to the evolution of MRI machines, postprocessing software and, above all, sequences. After infarction, and in chronic myocardial ischaemia, the degree of contractile dysfunction is one of the main determinants of longterm survival. The identification and quantification of viable dysfunctional myocardium and the possibility of improving its contractility after revascularisation improves patient prognosis and quality of life. In current clinical practice, myocardial viability is evaluated with stress echocardiography and nuclear methods. Thanks to its intrinsic characteristics and to the delayed-enhancement technique (DE-MRI), MRI has recently emerged as the only noninvasive modality able to provide a three-dimensional (3D) evaluation of cardiac viability with a multiparametric approach.

Imaging of post-traumatic cardiac rhabdomyolysis with normal coronary arteries.

Numerous cases of acute myocardial infarction (AMI) have been reported in the literature following closed chest injuries, due to post-traumatic dissection or thrombosis of a coronary artery. In the follow-up of AMI, wall thickness during diastole and systole provides important information on heart viability. Multidetector computed tomography (MDCT) is currently the only noninvasive instrumental investigation which provides an appreciable assessment of the coronary arteries, as well as heart wall thickness measurements. We describe and discuss the clinical and imaging findings, especially of MDCT, in a case of post-traumatic regional myocardial necrosis with normal coronary arteries.

Primary cardiac Burkett's type lymphoma: transthoracic echocardiography, multidetector computed tomography and magnetic resonance findings.

Although primary cardiac lymphoma is an extremely rare disease and is associated with high mortality, it is treatable when diagnosed appropriately. We describe the transthoracic echocardiography, 16-row multidetector computed tomography (16-MDCT) and magnetic resonance findings of primary cardiac lymphoma in an immunocompromised patient and review of the literature.

[Acute isolated infarct of the right ventricle with an unusual hemodynamic and electrocardiographic pattern]. / Infarto acuto isolato del ventricolo destro con inusuale quadro emodinamico ed elettrocardiografico.

The Authors reports on a case of isolated infarction of the right ventricle, with electrocardiographic pattern of non-transmural anterior myocardial infarction and haemodynamic profile suggestive of important diastolic disfunction. Clinical, angiographic and haemodynamic data are discussed along with review of the literature.

[Acute myocardial infarction in a case of obstructive cardiomyopathy of the left ventricle (author's transl)]. / Infanto acuto del miocardio in un caso di cardiomiopatia ostruttiva del ventricolo sinistro.

A case of acute myocardial infarction in 64 year old man with idiopathic hypertrophic obstructive cardiomyopathy of left ventricle is described. The Authors emphasize the rarity of association and that the diagnosis of obstructive cardiomyopathy in the elderly is always almost misinterpreted. This depends on the poor specificity of clinical and phonocardiographic findings, both basal and under pharmacological tests. The Authors point out that in adult patients with left ventricular idiopathic obstructive cardiomyopathy who must be operated also selective coronary angiography should be performed.