Biomedical subjects

M C Caputo

Publications and source records attributed to M C Caputo.

5 recordsLinked to original sources

PubMed2006

A methodology for space-time classification of groundwater quality.

Safeguarding groundwater from civil, agricultural and industrial contamination is matter of great interest in water resource management. During recent years, much legislation has been produced stating the importance of groundwater as a source for drinking water supplies, underlining its vulnerability and defining the required quality standards. Thus, schematic tools, able to characterise the quality and quantity of groundwater systems, are of very great interest in any territorial planning and/or water resource management activity. This paper proposes a groundwater quality classification method which has been applied to a real aquifer, starting from several studies published by the Italian National Hydrogeologic Catastrophe Defence Group (GNDCI). The methodology is based on the concentration values of several parameters used as indexes of the natural hydro-chemical water condition and of potential man-induced modifications of groundwater quality. The resulting maps, although representative of the quality, do not include any information on its evolution in time. In this paper, this "stationary" classification method has been improved by crossing the quality classes with three indexes of temporal behaviour during recent years. It was then applied to data from monitoring campaigns, performed in spring and autumn, from 1990 to 1996, in the plain of Modena aquifer (central Italy). The results are reported in the form of space-time classification table and maps.

Environmental Monitoring↗

PubMed2005

Nonlinear response of the benzene molecule to strong magnetic fields.

The fourth-rank hypermagnetizability tensor of the benzene molecule has been evaluated at the coupled Hartree-Fock level of accuracy within the conventional common-origin approach, adopting gaugeless basis sets of increasing size and flexibility. The degree of convergence of theoretical tensor components has been estimated allowing for two different coordinate systems. It is shown that a strong magnetic field perpendicular to the plane of the molecule causes a distortion of the electron charge density, which tends to concentrate in the region of the C-C bonds. This charge contraction has a dynamical origin, and can be interpreted as a feedback effect in terms of the classical Lorentz force acting on the electron current density.

Journal Article↗

PubMed2004

Calculation of the fourth-rank molecular hypermagnetizability of some small molecules.

A computational scheme has been developed within the framework of Rayleigh-Schrödinger perturbation theory to evaluate nonlinear interaction energy contributions for a molecule in the presence of an external spatially uniform, time-independent magnetic field. Terms connected with the fourth power of the perturbing field, representing the fourth-rank hypermagnetizabilities of five small molecules, have been evaluated at the coupled Hartree-Fock level of accuracy within the conventional common-origin approach. Gaugeless basis sets of increasing size and flexibility have been employed in a numerical test, adopting two different coordinate systems to estimate the degree of convergence of theoretical tensor components.

Journal Article↗

PubMed2004

Modeling solid-state effects on NMR chemical shifts using electrostatic models.

This paper presents a comparison of the embedded ion method (EIM) and the surface charge representation of the electrostatic embedding potential (SCREEP) method, two methods which can be used to calculate solid-state effects on NMR chemical shifts. The results in a selected group of compounds with known single-crystal solid-state NMR data and neutron diffraction structures, confirm that these effects are important in both (13)C and (15)N chemical shifts. The solid-state effects calculated by both methods are similar and of equal statistical quality when compared with the experimental data.

Algorithms↗

PubMed1995

Post-treatment management options for patients with lung cancer.

OBJECTIVES: The first objective was to identify variations in patient management practice patterns after potentially curative lung cancer surgery. Patient management practice patterns were expected to range from intensive follow-up to no active surveillance. The second objective was to measure whether intensity of follow-up was related to patient outcomes. METHODS: An 18-month retrospective analysis was conducted of 182 patients with low TNM stage (< or = IIIA) lung cancer who were surgically treated with curative intent over the 11-year period from 1982 through 1992 at the St. Louis Department of Veterans Affairs Medical Center. RESULTS: Patients were followed for a mean of 3.3 years, until death or the end of the study. Analyses of diagnostic test and outpatient visit frequency distributions and cluster analyses facilitated the identification of 62 nonintensively followed patients and 120 intensively followed patients. Both groups were comparable at baseline, and there were no significant differences in patient outcomes attributable to intensity of follow-up. Intensively followed patients did, however, live an average of 192 days longer than nonintensively followed patients. CONCLUSIONS: Significant variations in follow-up practice patterns can exist within a single health care facility. In this analysis, variations in test and visit frequency did not result in statistically significant differences in patient outcomes, though the survival difference between groups suggests that some benefit might exist. Only well-designed prospective trials are likely to answer the question of what constitutes optimal follow-up after potentially curative lung cancer treatment.

Case-Control Studies↗