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bounds to the PM and AM noise of the second output harmonic, computed by Eqs. (1) and (2)-(6), are shown in Figure 2. The uncertainty on the output PM noise is of the order of 20.3 dB and is almost independent of fD. The expected output-to-input PM noise ratio of 6 dB is obtained for 3 = 0 within 50.005 dB, which indirectly confirms that 0 is the most likely value of 3.The output AM noise is very close to that of the source, with virtually zero uncertainty for f D 2 1 kHz. Only at very low frequency deviations and for 3 > 0 is some loss of numerical accuracy observed, due to the very high PM-to-AM noise ratio that makes the computation ill conditioned. It is thus clear that a valid noise analysis can indeed be performed by Eq. (6) on the basis of a simplified statistical description of the noisy source, consisting of PM and AM noise only. ABSTRACT In this article we present a modified least-squares boundary residual (LSBR) method for the rigorous analysis of microwave integrated circuits (MICs). The method is relatively convergent and a semianalytical relative convergence criterion is found to be very important in optimizing its convergence. Moreover, the problem of the poor conditioning of the least-squares matrices has been rigorouslv resolved.ABSTRACT A simple method for obtaining optical transmission spectra of AI, Ga,.,As epilayer by translucent A B wax is presented. Absorp-tion spectra are measured for x in the range of 0 < x < 0.8. For the Tlii Ti( energy bandgap, the aluminum concentrations, calculated from the experimental data with a formula derived by the ray-optics merhod, are in good agreement with those reported. 0 1992 John Wile! & Sons, Inc.

Background and aims Epidemiology of hepatocellular carcinoma (HCC) is changing in most areas of the world. This study aimed at updating the changing scenario of aetiology, clinical presentation, management and prognosis of HCC in Italy during the last 15 years. Methods Retrospective analysis of the Italian Liver Cancer (ITA.LI.CA) database included 6034 HCC patients managed in 23 centres from 2004 to 2018. Patients were divided into three groups according to the date of cancer diagnosis (2004‐2008, 2009‐2013 and 2014‐2018). Results The main results were: (i) a progressive patient ageing; (ii) a progressive increase of non‐viral cases and, particularly, of ‘metabolic’ and ‘metabolic + alcohol’ HCCs; (iii) a slightly decline of cases diagnosed under surveillance, but with an incremental use of the semiannual schedule; (iv) a favourable cancer stage migration; (v) an increased use of radiofrequency ablation to the detriment of percutaneous ethanol injection; (vi) improved outcomes of ablative and transarterial treatments; (vii) an improved overall survival (adjusted for the lead time in surveyed patients) in the last calendar period, particularly in viral patients; (viii) a large gap between the number of potential candidates (according to oncologic criteria and age) to liver transplant and that of transplanted patients. Conclusions During the last 15 years several aspects of HCC scenario have changed, as well as its management. The improvement in patient survival observed in the last period was likely because of a larger use of thermal ablation with respect to the less effective alcohol injection and to an improved management of intermediate stage patients.

Reliable biomarkers are of great clinical value in predicting cancer occurrence/recurrence, anticipating its detection at an asymptomatic stage, supporting the radiological diagnosis, stratifying patients for prognosis and proper therapy, and measuring the response to treatment. Despite the plethora of biomarkers proposed for hepatocellular carcinoma (HCC), the first one identified, α-fetoprotein (AFP), remains the most utilized. This article reviews the lights and shadows of AFP as a surveillance test for patients at risk of HCC, and as a diagnostic test for those with chronic liver disease and a suspected hepatic mass. Moreover, the article scrutinizes the large body of evidence supporting the prognostic relevance of AFP in patients undergoing both curative and palliative treatment of HCC and the growing importance attributed to this biomarker (as a static or a dynamic variable) in the selection of potential candidates for liver transplantation. In fact, the inclusion of AFP among transplant criteria would improve the ability of identifying poor candidates due to an unacceptable risk of HCC recurrence regardless of tumor burden, and of adopting flexible morphological selection criteria.