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L Bonomo

Publications and source records attributed to L Bonomo.

At least 37 records · Page 2Linked to original sources
PubMed2001

Simplified and Monod kinetics in one-dimensional biofilm reactor modelling: a comparison.

A theoretical study supported by some experimental tests has been carried out with the aim of comparing one-dimensional (1-D) biofilm reactor models that use simplified (zero- and first-order) and Monod kinetics. Two different situations have been compared: one rate-limiting substrate with or without liquid film diffusion. The results obtained show that the use of a simplified kinetic approach compared to the Monod kinetic approach determines (1) an unjustified overestimate of the removal rate, especially for thin biofilms, and (2) an excessive overestimate of the liquid film layer thickness necessary to justify high kinetic orders. Even if recent research projects show that biofilm structure is more complicated than the one assumed in the modelling approach used in this study, nevertheless 1-D models still now continue to be the only ones that can reasonably support process engineers in biofilm reactor design, due to their intrinsic simplicity and the need for small sets of input data and parameters that can be obtained theoretically or often empirically.

Biofilms↗
PubMed2001

Some economic considerations on wastewater reclamation for irrigation, with reference to the Italian situation.

The purpose of this work is to check construction and operation costs for simplified post-treatment trains able to produce water displaying a quality suitable for different agricultural uses. Having in mind the quality of most of surface waters in Italy, the main parameters to control for a general purpose reclaimed water supply are microbial quality and TSS content. Therefore a contact filtration followed by disinfection is to be considered the minimum option, while the use of polishing ponds can be strictly limited in many Italian regions due to the area requirements and to the need to provide a full lining of bottom and levees. Some data referring to surface waters quality and to the Italian epidemiological situation are given. On the basis of the current Italian situation, the construction and operation cost increases due to a polishing section, downstream a standard municipal WWTP, are evaluated and the impact of different technical choices is shortly discussed (disinfection options, chemicals, etc.). Some considerations about the link existing in Italy between the cost of water for irrigation and the agricultural economy are made.

Agriculture↗
PubMed2000

The binding ability of iron bonded to porphodimethene: structural, magnetic, and electronic relationship to iron porphyrin complexes.

The availability of the parent compound, meso-hexaethylporphodimetheneiron(II), [(Et6N4)Fe] (2), of this report results from a novel synthetic methodology that makes [Et6N4Li2] (1) easily available. The major focus is on how the axial positions, which are the key reactive sites in metalloporphyrins, and the electronic configuration of the metal can be affected by the breakdown of the aromaticity of the porphyrin skeleton and by the nonplanar conformation of the ligand. DFT calculations indicate a 3B1(dz2)1(dyz)1 ground state for 2 versus the 3A2(dxz)1(dyz)1 ground state in the porphyrin analogue. The intermediate-spin state (S = 1) of 2 changed drastically upon addition of one or two axial ligands, as hexacoordination is preferred by iron(II). The hexacoordinate complexes [(Et6N4)Fe(L)(L')] (L = L' = THF, 3; L = L' = Py, 4; L = PhNO, L' = Py, 14) have been isolated and structurally characterized. Strong-field ligands lead to a low-spin diamagnetic state for iron(II), namely for complexes 4-7, 9, and 14, whereas 3 is a typical d6 high-spin complex, as is the pentacoordinate [(Et6N4)Fe(CN)]Bu4N (8). The structural analysis showed common features for 6, 7, 9, and 14: i) a small displacement of the metal from the N4 plane, and ii) an N4 cavity, larger than that in the corresponding porphyrins, affecting the Fe-N bond lengths. The 1H NMR spectrum is quite diagnostic of the two-fold symmetry in the diamagnetic hexacoordinate complexes, revealing either a D2h or a C2v symmetry. The CO stretching frequency (1951 cm(-1)) in complex 6 probes the good electron density at the metal. The one-electron oxidation of 2 led to pentacoordinate iron(III) derivatives [(Et6N4)Fe(Cl)] (10), [(Et6N4)2Fe2(mu-O)] (11), and [(Et6N4)2Fe2(mu-p-OC6H4-O)] (12). Complex 10 is a typical high-spin iron(III) (5.85muB at 298 K), while 11 and 12 behave as antiferromagnetic coupled iron(III) (J = -9.4cm(-1), 12, and J = -115cm(-1), 11). In complexes 10, 11, and 12 iron is sitting in a quite distorted square pyramidal geometry, in which the ligand displays a very distorted roof conformation with different degrees of ruffling. Distinctive structural and magnetic features have been found for the nitrosyl derivative [(Et6N4)Fe-NO], which has a low-spin state (S = 1/2) and the following structural parameters: Fe-N-O, 147.3(2) degrees; Fe-N, 1.708(2) A; N-O, 1.172(3) A. A comparative structural, magnetic, and theoretical analysis of the compounds listed above has been made with the analogous porphyrin derivatives. The detailed structural investigation has been mapped through the X-ray analysis of 2, 7, 8, 9, 11, 13, and 14.

Journal Article↗
PubMed2000

Topographic organization of the human primary and secondary somatosensory areas: an fMRI study.

The topographical organization of SI and SII somatosensory areas was investigated using fMRI at 1.5 T and electrical sensory stimulation. Electrical stimuli were delivered unilaterally to the median nerve at the wrist and to the tibial nerve at the medial malleolus, during a block paradigm study. In all subjects, activation was observed, contralaterally to the stimulated side, in the post-central gyrus, in the posterior parietal cortex, in the mesial pre-frontal region and, bilaterally, in the supratemporal region at the level of the Sylvian fissure. The latter region, corresponding presumably to SII, showed a rough but clearcut topographical organization, with the median nerve areas located more posteriorly. In addition, weaker activations were observed in some subjects in the ipsilateral mesial prefrontal region and in the ipsilateral posterior parietal cortex. Information contained in the present study represent an interesting database for future investigations on the effects of sensorimotor learning in normal individuals on plastic reorganization following a lesion of the primary sensorimotor centers, i.e. in stroke patients, on the topography and balance between upper and lower limb representations in primary and secondary somatosensory cortices.

Adult↗
PubMed2000

MRI T-staging of laryngeal tumours: role of contrast medium.

Our aim was to evaluate the relative diagnostic accuracy of MRI without contrast medium and MRI before and after contrast medium in the assessment of T-staging of laryngeal tumours. We studied 25 men (mean age 51.8, range 41-61) with laryngeal squamous cell carcinomas, using Spin-echo (SE) T1-weighted and fast SE T2-weighted sequences. The T1-weighted sequences were then repeated after gadolinium-diethylene-triaminepenta-acetic acid (Gd DTPA) 0.1 ml/kg. All patients then underwent biopsy and surgery. Two radiologists independently assessed the anonymised images by filling-out two multiple-choice forms, one for each technique, at a 2 week interval. The forms included a judgement concerning tumour identification and infiltration of the anterior commissure, supraglottic region, arytenoid cartilage, Morgagni's ventricle, paraglottic space, thyroid and cricoid cartilages, thyro-hyo-epiglottic space, vocal cords, subglottic region, and epiglottis. Similar forms were filled out by the surgeon and the pathologist after surgery. The sensitivity, specificity and diagnostic accuracy of MRI were unaffected by the use of contrast medium. Since it did not provide additional staging information, its continued routine use in these cases is not justified.

Adult↗
PubMed2000

Malignant pleural disease.

The vast majority of pleural neoplasms invade the pleura secondarily and can be seen in patients with bronchogenic carcinoma, breast cancer, lymphoma, and ovarian or gastric carcinoma. Primary pleural neoplasms are less common, although they have developed notoriety since the up-surge of malignant mesothelioma and the knowledge of its connection to asbestos exposure. Other malignant primary tumors include localized fibrous tumor and pleural liposarcoma. In most patients with diffuse malignant pleural disease the chest radiograph shows pleural effusion with or without pleural thickening. Computed tomography (CT) usually provides precise localization and extent of the disease and may be of value in assessing chest wall and mediastinal involvement. In specific situations, magnetic resonance (MR) may be useful as a problem-solving tool when CT findings of chest wall or diaphragmatic invasion are equivocal or in patients with contraindication to intravenous administration of ionic contrast material.

Asbestos↗
PubMed2000

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Journal Article↗
PubMed2000

[Magnetic resonance angiography of the peripheral vessels with automatic moving bed infusion tracking].

PURPOSE: To investigate the actual diagnostic reliability of the Mobitrack technique with a slow intravenous infusion of paramagnetic contrast agent (CA) in MR Angiography of the peripheral arterial district. MATERIAL AND METHODS: Twelve healthy volunteers (mean age: 34) with no personal or family history of peripheral arterial pathologic conditions, underwent MR Angiography of the peripheral vascular district. A 1.5 T superconductive magnet equipped with automatic table feed was used. In the preliminary phase, the circulation time at the abdominal aorta was optimized and customized for each patient. This was done by performing a pre-targeting Fast Field Echo 2D (FFE 2D) sequence with intravenous administration of 1-2 mL CA by an injector, to evaluate the delay time. A 2D Time of Flight (2D TOF) sequence was then performed for topographic purposes. The partially overlapping volumes were acquired using Fast T1-weighted sequences, intravenous CA administration and an automatic table feed of 10 mm/s. A Fast Field Echo 3D (FFE 3D) T1-weighted sequence with TR/TE/FA: of 6.3/1.6/40 degrees and a slice thickness of 1.5 mm were also performed. Thirty to forty mL CA were slowly administered intravenously at a rate of 0.3-0.6 mL/s. Two blinded readers independently evaluated the images giving one of three diagnostic judgements: 1) arteries were well visualized, 2) heterogeneous arteries with(out) the presence of veins, and 3) arteries seen poorly or not at all. The first two judgements were considered diagnostic. The readers considered 19 different anatomical districts for each patient, giving a total of 190 evaluations. RESULTS: A blinded evaluation of the readers judgements did not indicate a statistically significant difference (agreement: 100%). Overall, 82% of the images were rated as 1, 8.5% as 2 and 8.4% as 3. DISCUSSION: In 174/190 judgements the vessels were rated as 1 or 2, that is of diagnostic value. Judgement 3 was always due to the inability to visualize the medial and/or distal third of the arterial circulation of the leg. CONCLUSIONS: The results of this technique optimization study confirm the overall validity of the Mobitrack technique. However they also indicate that further technical advances are required to ensure maximum diagnostic accuracy in this vascular district.

Adult↗
PubMed1999

Increased levels of lactoferrin in synovial fluid but not in serum from patients with rheumatoid arthritis.

Lactoferrin is a multifunctional immunoregulatory protein, stored in specific granules of neutrophil granulocytes, from which it is released following cell activation. As activated neutrophils play a crucial role in the destruction of synovial joints in rheumatoid arthritis, we evaluated lactoferrin concentration in synovial fluid and sera from 21 patients with rheumatoid arthritis and 11 patients with osteoarthritis. We also measured lactoferrin levels in sera from 12 healthy controls. Lactoferrin was measured by a solid-phase inhibition immunoassay. Median lactoferrin levels were significantly higher in synovial fluid from rheumatoid arthritis than from osteoarthritis patients (P = 0.0002). In contrast, no significant difference was found between serum lactoferrin from patients with rheumatoid arthritis or osteoarthritis compared with normal controls. In patients with rheumatoid arthritis, lactoferrin concentrations were higher in synovial fluid than in sera (P = 0.036). In both rheumatoid arthritis and osteoarthritis no correlation was found between serum and synovial fluid lactoferrin (P = 0.51 and P = 0.5, respectively). In synovial fluid from patients with rheumatoid arthritis, lactoferrin concentrations correlated with neutrophil granulocyte count (P < 0.0001), but neither serum nor synovial lactoferrin levels correlated with disease activity (P = 0.32 and P = 0.25, respectively). In conclusion, lactoferrin is a reliable marker of neutrophil activation at sites of inflammation in rheumatoid synovitis, but does not represent a marker of disease activity.

Adult↗
PubMed1999

Retinopathy in systemic lupus erythematosus: pathogenesis and approach to therapy.

The starting point in the assessment of SLE-retinopathy is the clinical examination by ophthalmoscopy and retinal fluorescein angiography. It is noted that two major clinical forms of retinopathy may occur in SLE; (1st) the "classic" type characterized by cotton-wool spots with or without intraretinal hemorrhages, and (2nd) the thrombosis of larger retinal blood vessels, such as central or branch arteries/veins. However, a well-defined pathogenetic classification of SLE-retinopathy has still not been proposed as yet. A practical classification based on the pathogenesis could be of aid to commence a more appropriate treatment. The aims of this paper are; (1st) to focus on the most implicate mechanisms of retinal vascular disease in SLE, (2nd) to mention the most common features associated with the different forms of retinopathy, and finally (3rd) to assess the prevalence of retinopathy in SLE. In our opinion, it seems that two major types of retinopathy exist in SLE: firstly, the Hughes' retinopathy due to antiphospholipid-induced retinal vascular thrombosis, for which anticoagulation is the best treatment, and secondly, the "classic" retinopathy in which at least two major causes could be associated; vasculitis and accelerated atherosclerosis. In patients with "classic" retinopathy, the most appropriate treatment still needs to be established. If "classic" retinopathy is due to vasculitis, immunosuppressive drugs should be administered, while if atherosclerosis play an etiologic role, a prophylaxis with antioxidants or the use of low-dose aspirin should be assessed.

Adolescent↗
PubMed1999

Contrast-enhanced MR angiography (CE MRA) in the study of the carotid stenosis: comparison with digital subtraction angiography (DSA).

PURPOSE: To determine sensitivity, specificity and diagnostic accuracy of contrast-enhanced magnetic resonance angiography (CE MRA) compared to digital subtraction angiography (DSA) in the study of carotid stenosis. METHODS AND MATERIAL: We studied 23 patients with suspected cerebro-vascular insufficiency by carotid stenosis. Diagnostic examinations by means of CE MRA and DSA were carried out within 24 hours of each other. A 1.5 T superconductive magnet (Signa-General Electric) was used for CE MRA. This technique was performed using a fast spoiled gradient echo recalled (SPGR) sequence acquired in coronal plane 13 sec after injection of contrast medium. Imaging parameters were: TR/TE/FA 8 msec/1 msec/60 degrees, matrix 256 x 128, 1 excitation, FOV 18 x 13 cm, 28 slices per slab, slice thickness of 1 mm, acquisition time of 32 sec. The post-processing was performed using maximum intensity projection (MIP) and targeted MIP. For DSA examinations a Politron 1000 VR unit (Siemens) was used. RESULTS: In the identification and quantification of lesions, CE MRA showed values of 100%. In particular, in comparison to DSA, CE MRA was accurate in diagnosing all true negative and positive cases. The location of stenosis evaluated with CE MRA agreed in all cases with DSA. CONCLUSION: In our experience CE MRA proved to be a very valuable technique in diagnosing carotid stenosis, showing the same diagnostic accuracy as DSA. In this way CE MRA appears to be a substantial alternative technique to conventional MRA and other non-invasive diagnostic methods.

Aged↗
PubMed1998

Size of pancreas in children and adolescents with type I (insulin-dependent) diabetes.

PURPOSE: The aim of this study was to evaluate the influence of insulin-dependent diabetes mellitus (IDDM) on the size of the pancreas in children. METHODS: Pancreas size was evaluated sonographically in a group of 60 diabetic children and adolescents, aged 3-15 years, and 60 sex- and age-matched healthy controls. RESULTS: A significant reduction in pancreatic area and other parameters was found in diabetic patients particularly in children aged 8-12 and 13-15 years. The pancreas was larger in children 3-7 years old who had had IDDM for 2 years of less (mean size, 8.61 cm2) than in children 8-12 and 13-15 years old who had had IDDM for more than 5 years (mean size, 8.06 and 8.40 cm2, respectively). An inverse correlation between area of the pancreas and duration of IDDM was seen in all age groups (p < 0.05). CONCLUSIONS: Diabetes affects the growth of the pancreas in children with IDDM. Sonography can be used to noninvasively evaluate the influence of the disease on pancreas size.

Adolescent↗
PubMed1998

Pulmonary veins: magnetic resonance angiography anatomy.

OBJECTIVE: to optimize magnetic resonance angiography technique for the selective study of the anatomy of pulmonary veins. MATERIALS AND METHODS: twenty consecutive patients (13 males and seven females; mean age 30.5 years) prospectively studied were enrolled. Magnetic resonance angiography was performed using a 1 T superconductive magnet and three dimensional time of flight technique (3D TOF). Imaging with steady-state free precession sequence during intravenous infusion of contrast medium (Gd DTPA 0.2 mmol kg(-1)) administration was employed using the following parameters: FA 20 degrees, TR 58 ms, TE 6 ms, MA 192 x 256, NEX 1, slice thickness 4 mm and slice orientation on the Z and Y planes. RESULTS: in the right lung magnetic resonance angiography well visualized 124 venous vessels on the coronal plane versus 106 venous vessels on the sagittal plane, whereas in the left lung magnetic resonance angiography visualized 96 vessels on the coronal plane versus 44 visualized on the sagittal plane. Our data suggest that 3D time of flight with contrast medium is a promising evaluation technique for pulmonary veins, and that combined evaluation of acquisitions on coronal and sagittal planes allows the visualization of a higher number of venous vessels. CONCLUSION: 3D time of flight with contrast medium and without breath-hold permits to visualize a venous vascular map of the lungs.

Adult↗