A functional polymeric material based on hybrid electrochemically controlled junctions

A thin film polymeric junction was fabricated which yields a molecular electronic device functionally able to learn, i.e. to respond coherently to an external training signal. The fabricated structure is based upon electrochemical control of electronic current in a conducting polymer in contact with a solid electrolyte polymer. This functional behavior bears some resemblance to simple cases of biological learning processes. We report a comprehensive electronic characterization of the device function. Additional study was performed in order to estimate the possibility of the integration of such kinds of devices in statistical adaptive networks.     

Hepatic cholesterol and bile acid metabolism in subjects with gallstones: comparative effects of short erm feeding of chenodeoxycholic and ursodeoxycholic acid

The activity of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and 7alpha-hydroxylase, the enzymes controlling the rate of hepatic synthesis, respectively, of cholesterol and bile acids, and the microsomal cholesterol content were evaluated in 25 patients with cholesterol gallstones and 17 subjects without gallstones. The same quantities were estimated in 16 additional patients with gallstones given chenodeoxycholic (CDCA) or ursodeoxycholic acid (UDCA) at a dose of 15 mg/kg per day in order to investigate the comparative effect of a short term (7 days) administration of the two bile acids on the hepatic sterol metabolism. As compared to the controls, subjects with gallstones exhibited a 36% decrease of 7alpha-hydroxylase (26.8 +/- 6.2 versus 41.7 +/- 4.2 pmol/min per mg protein) and a 24% increase of the microsomal cholesterol (78.7 +/- 15.3 versus 63.1 +/- 18.1 nmol/mg protein). Although higher in the gallstone patients, the activity of HMG-CoA reductase did not differ significantly in the two groups of subjects. Administration of CDCA and UDCA changed the bile acid pool composition so that the fed bile acid predominated in the bile (mean CDCA 73% and mean UDCA 54%). Bile lipid composition did not appreciably change. In the eight subjects treated with CDCA the activity of HMG-CoA reductase was reduced to 45% of the value of untreated subjects (27.9 +/- 14.5 versus 63.5 +/- 25.3 pmol/min per mg protein) whereas in the eight subjects treated with UDCA the same enzyme showed a twofold increase (123.5 +/- 20.9). In the treated groups 7alpha-hydroxylase activity was somewhat decreased but the values did not differ significantly from those of the untreated subjects. Microsomal cholesterol content decreased with CDCA (64.8 +/- 11.6 nmol/mg protein) as well as with UDCA (59.1 +/- 10.1) treatment; however in the latter the difference attained statistical significance (P < 0.05). Altogether the results would suggest that in the liver of patients with gallstones the conversion of cholesterol to bile acids is somewhat reduced, and that changing the bile acid pool composition, by exogenous bile acid feeding, has disparate effects on hepatic cholesterol synthesis. The findings could represent the acute changes produced by bile acid feeding, however they could imply that the effects of two bile acids in dissolving cholesterol gallstones might not be related only to the changes in hepatic sterol metabolism.-Carulli, N., M. Ponz De Leon, F. Zironi, A. Pinetti, A. Smerieri, R. Iori, and P. Loria. Hepatic cholesterol and bile acid metabolism in subjects with gallstones: comparative effects of short term feeding of chenodeoxycholic and ursodeoxycholic acid.     

Testicular lymphomas. A clinico-pathological study of 5 cases and a review of the literature]

The authors describe five consecutive patients with testicular non Hodgkin lymphoma, evaluate the clinical and histological characteristics and underline the importance of a chemotherapy approach both at diagnosis and at relapse. A review of the literature is carried on and particularly about the prognostic factors, the correlation with Ebstein Barr virus and the more recent integrated therapeutical approaches.     

Role of the solid electrolyte composition on the performance of a polymeric memristor

The role of the solid electrolyte composition on the properties of an electrochemically controlled conducting polymer–electrolyte junction (organic memristor) was investigated, with the purpose of optimizing its memory properties and non-linear characteristics. Along with electrical measurements, SEM imaging and FTIR characterization were performed in order to correlate the results with the film morphology and differences in the vibrational spectra, respectively. Best results were obtained with a slightly acidic nature of the electrolyte dopant which allows to avoid the secondary doping of the structures and shifts the reduction potentials to negative values. The first achievement simplifies the technology of the memristor fabrication, while the second one allows to work in the pulse mode without any dc offset of the input signal as well as to fabricate complex networks of such elements without any risk to exclude some elements from the process of the formation of signal transfer pathways.