The present study investigated whether the lack of enzyme increase is reason enough to exclude necrosis in patients with ischemic heart disease who develop electrocardiographic sustained ST-T changes ...in the absence of Q waves. In 15 consecutive patients with angina who developed sustained ST-T changes during hospitalization, the presence of myocardial necrosis was investigated by a prospective multiparametric approach. Serum enzymes and myoglobin, pyrophosphate uptake, 2-dimensional echocardiography, perfusion scintigraphy, left ventriculography and coronary angiography were evaluated. According to creatine kinase and creatine kinase-MB peak at twice the upper normal value, the diagnosis of acute myocardial infarction applied only to 40% of patients. However, myoglobin was positive in 80% and a perfusion defect could be documented by an electrocardiographic gated microsphere technique in 100% of patients. The positivity of myoglobin increased to 100% and of creatine kinase and creatine kinase-MB to 87 and 60%, respectively, when a peak value twice the individual lowest value was considered for positivity. The 100% presence of perfusion defects associated with the high prevalence of both positive pyrophosphate uptake (87%) and regional dyssynergies (87 and 73%, respectively, by left ventriculography and echocardiography) strongly suggest that sustained (greater than or equal to 7 days) ST-T changes in this population were indicative of myocardial necrosis. Thus, by conventional enzymatic approach, diagnosis of non-Q-wave infarction can be missed in a sizable number of patients and present important clinical implications.
As already reported ENEA is engaged in the realization of a 12 T wind and react Nb/sub 3/Sn coil, a subsize magnet designed to simulate many technological problems to be faced in NET-ITER magnets. ...EM-LMI and Ansaldo are the industrial partners in this project. A preliminary winding has been built and successfully tested. This winding has been cut in pieces and carefully inspected to be sure that the impregnation process after the heat treatment works well. No particular flaws have been detected. Then manufacturing of the 12 T magnet has been started and completed in about three months. Heat treatment, impregnation and electrical tests at 300 K have been successfully performed and the magnet is now ready for final tests. In order to obtain the most significant scientific and technological informations from this magnet, the original test programme (insertion of the coil in the SULTAN facility) has been modified according to a decision of the Fusion Technology Steering Committee (FTSC) of EURATOM. Details of the new test programme are given in the paper.< >
Dissection of the aneurysm is the most dangerous step during graft replacement of the descending thoracic aorta. Sudden hemorrhage may follow wall rupture or disruption of major collaterals before ...the aorta can be clamped. A simple modification of the classic Gott is illustrated, which makes the shunt work also as a partial bypass if needed, with rapid reinfusion of blood losses. Nineteen of 25 patients requiring resection of descending aortic aneurysms from 1982 to 1990 were treated with this method with no mortality.
With reference to colorectal cancer, we have reconstructed a Molecular Interaction Map downstream of TGFβ, Wnt and EGF-family. Based on an extensive and systematic direct/indirect data extrapolation ...from several dozens of published experimental papers, and some data interpolation that could fit with the general behavior of this signaling-network region, we were able to obtain an operative mathematical simulation model. We could simulate normal conditions of the network, behavior in the presence of important colorectal cancer mutations, behavior in the presence of virtual drug inhibitors of different specifically altered onco-proteins affected by excess of function. The dynamic behavior of the simulation seems quite reasonable, in terms of what is known about the physiology and the pathology of this signaling-network region. Preliminary experimental verification experiments look encouraging.
One-dimensional polyelectrolytes are proposed as molecular devices based on soliton propagation. The use of such "molecular wires" as delay lines or shift registers raises the problem of their ...electrical screening, because, when a large number of these wires are densely packed, cross-talking between them might occur. In order to overcome such a drawback, a detailed study of the polyelectrolyte behavior in an ionic solution has been developed, under equilibrium conditions. The results bring into evidence a condensation process, around each molecular wire, of the mobile ions in the solution. The consequent self-screening effect could be relevant in reducing cross-talking.
Design and Construction of an Arbitrary Waveform Generator Caviglia, Daniele D.; De Gloria, Alessandro; Donzellini, Giuliano ...
IEEE transactions on instrumentation and measurement,
1983-Sept., Letnik:
32, Številka:
3
Journal Article
Recenzirano
The purpose of this paper is to describe the design and characteristics of an arbitrary waveform generator, built at the Biophysical and Electronic Engineering Division of the Electrical Engineering ...Department of the University of Genoa, which exhibits the following features: a) The signal waveform is any band-limited periodic signal, whose frequency content ranges from 0.125 mHz up to 30 MHz. The low-frequency limit has been chosen in order to meet the needs of bioengineering, mechanical, and chemical applications. The high-frequency limit covers, for instance, TV and image processing applications. b) The noise level is at least 66 dB below the maximum signal level. c) Typical distortion is less than -66 dB. d) The generator's performance can be easily improved, depending on the availability of up-to-date solid-state devices, without changing its design.
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