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Biomedical subjects

S Ridella

Publications and source records attributed to S Ridella.

15 recordsLinked to original sources
PubMed2000

Digital VLSI algorithms and architectures for support vector machines.

In this paper, we propose some very simple algorithms and architectures for a digital VLSI implementation of Support Vector Machines. We discuss the main aspects concerning the realization of the learning phase of SVMs, with special attention on the effects of fixed-point math for computing and storing the parameters of the network. Some experiments on two classification problems are described that show the efficiency of the proposed methods in reaching optimal solutions with reasonable hardware requirements.

Algorithms↗
PubMed1987

The physical state of intranuclear water and ions: changes during cell proliferation and chemically induced carcinogenesis.

The complex dielectric constant of small quantities of liver nuclei in various functional states was measured in the frequency range of 50-2,000 MHz using an Automatic Network Analyzer. From these measurements, through an electric model of macromolecules in solution, several quantities such as ion content, bound water, and free water have been estimated. Unique changes in the physical state of intranuclear water and ions were then apparent in the resting liver nuclei immediately following induced cell proliferation, as compared to nuclei either from early carcinogen-altered hepatocytes or from late selected carcinogen-initiated hepatocytes. Possible implications of these findings are discussed in terms of the molecular events controlling chemically-induced neoplastic transformation.

Animals↗
PubMed1984

The systemic effect of cancers on human sera proton NMR relaxation times.

In animal models of cancer, an elevation of T1 and T2 in uninvolved tissues and in the blood of tumor bearing animals has been termed "the systemic effect." This study reports T1 values in sera of human patients from Genoa, Italy, with several types of cancer and non-cancerous diseases. T1 values were significantly elevated over normal controls (1628 +/- 113 ms) in colorectal cancers (1725 +/- 149 ms) and stomach cancers (1817 +/- 219 ms). However a systemic effect was not demonstrated in acute myeloid leukemia, chronic lymphatic leukemia, chronic myeloid leukemia, or plasma cell myeloma, or in pancreatic and lung cancers. Noncancerous states of cirrhosis, chronic hepatitis, and monoclonal gammapathies did not show a T1 elevation. In general, T1 values of sera correlated with protein content of the sera; however, a disproportionate contribution of gamma-globulin protein on water proton relaxation times was observed in several cases.

Colonic Neoplasms↗
PubMed1982

Evaluation of electrical fields inside a biological structure.

A digital computer simulation has been carried out of exposure of a cell, modelled as a multilayered spherical structure, to an alternating electrical field. Electrical quantities of possible biological interest can be evaluated everywhere inside the cell. A strong frequency selective behaviour in the range 0-10 MHz has been obtained.

Biophysical Phenomena↗