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Biomedical subjects

L Campanella

Publications and source records attributed to L Campanella.

61 records · Page 4Linked to original sources

Further applications of a new biosensor method for dating cellulosic finds.

Using a cellulosic material dating method recently proposed by three of the authors of the present article further applications to real samples are discussed. In the first instance, to wood samples, that is, to a type of sample for which the method was specifically developed but with the samples differing widely in age, and then to textile or paper samples. Of course in the latter two cases the results obtained are still quite preliminary, above all because of the difficulty of procuring certainly dated samples of this type.

Archaeology↗

Determination of compounds with anticholinesterase activity in commercial drugs by a new enzyme sensor.

A suitable enzyme sensor for the analysis of anticholinesterase compounds of pharmaceutical interest is described. It is based on the competitive inhibiting properties of these compounds on the enzyme butyrylcholinesterase and it is constituted by a hydrogen peroxide amperometric electrode modified by a superimposed Nylon membrane containing two chemically immobilized biological mediators (butyrylcholinesterase and choline oxidase). Some applications to the analysis of several pharmaceutical forms containing different compounds showing anticholinesterase activity are also reported and evaluated.

Alcohol Oxidoreductases↗

Analytical comparison of an enzyme-amperometric method for chlorocresol determination in ointments with colorimetry and liquid chromatography.

The direct determination of chlorocresol in n-hexane extracts of commercial ointments was successfully performed using an enzyme-amperometric probe for analysis of phenols and working in previously characterized and optimized non-aqueous solvents. The analytical data obtained were compared with those found by using classical HPLC or chemical spectrophotometric method for determination of phenols.

Biosensing Techniques↗

Analysis of L-dopa in pharmaceutical preparations and of total phenols content in urine by means of an enzyme-amperometric sensor.

An enzyme-amperometric method is proposed for the analysis of total phenols and L-dopa; the method is based on the enzyme tyrosinase, which is immobilized in a Nylon membrane and coupled to an oxygen gas-diffusion amperometric electrode. The method was applied to the determination of total phenols in urine and to L-dopa in formulations and was evaluated as a promising alternative to currently adopted methods, e.g. to a classical spectrophotometric technique, chosen as a reference method.

Biosensing Techniques↗

Cholanic acids determined in commercial drugs by means of a new ISFET device.

An ISFET device selective for cholanic acids, based on a PVC-sebacate membrane, containing benzyldimethylcetylammoniumcholate as exchanger, has been prepared, characterized and applied to the determination of cheno or ursodeoxycholic acid content of commercial pharmaceutical drugs and critical micellar concentration (CMC) values for cholate, deoxycholate and chenodeoxycholate. The results are compared with those obtained using previously described polymeric membrane sensors based on the same exchanger.

Calibration↗

Lecithin determination in foods and drugs by an amperometric enzymatic sensor.

A new enzymatic-amperometric method for the determination of lecithin as an additive in foods and as a component of commercial drugs is proposed. The method is based on a detector realized with two enzymes, choline oxidase and phospholipase D, the former immobilized, the latter free in solution, and by an oxygen Clark electrode. The experimental conditions were investigated in order to obtain wide applications with different samples. Extraction or dissolution of the samples in ethanol proved satisfactory. The precision of the method was found to be about 1.5%, inaccuracy less than or equal to 4%. Correlation between the proposed enzymatic-amperometric method and an enzymatic-spectrophotometric reference method was satisfactory.

Alcohol Oxidoreductases↗

Identification of different types of imperial age marble finds using instrumental chemical analysis and pattern recognition analysis.

A physical-chemical characterisation of several marbles frequently used in ancient times for artistic or decorative purposes was performed in support the work of historians and restorers. The data were obtained using several different types of instrumental chemical methods (Thermogravimetry, Differential Thermal Analysis, X-ray Diffractometry and ICP Plasma Emission Spectroscopy) and have been summarised in short tables. The data have already proved useful in the identification of a small number of finds (statues or architectonic elements) from Ancient Rome (Imperial Age, 2nd-3nd cent. A.D.) for the purpose of which also a well-known pattern recognition analysis software package was used for data processing. In practice, the research showed that an organised set of chemical data obtained using several modern instrumental methods can provide a valid basis for the reasonably rapid and reliable identification of the type of marble used to make artistic artifacts that have not yet been subjected to typological study.

Calcium Carbonate↗