190 research outputs found
Environmental evaluation of remediation technologies for polluted groundwater through LCA methodology
La bonifica di acquiferi contaminati è una pratica che oggi dispone di diverse soluzioni a livello tecnologico, caratterizzate tuttavia da costi (ambientali ed economici) e problematiche tecniche di entità tale da rendere in alcuni casi poco conveniente la realizzazione dell’intervento stesso. Per questo motivo sempre maggiore interesse viene rivolto nell’ambito della ricerca alle tecnologie di bioremediation, ovvero sistemi in cui la degradazione degli inquinanti avviene ad opera di microorganismi e batteri opportunamente selezionati e coltivati.
L’impiego di queste tecniche consente un minor utilizzo di risorse ed apparati tecnologici per il raggiungimento degli obiettivi di bonifica rispetto ai sistemi tradizionali.
Il lavoro di ricerca presentato in questa tesi ha l’obiettivo di fornire, tramite l’utilizzo della metodologia LCA, una valutazione della performance ambientale di una tecnologia di bonifica innovativa (BEARD) e due tecnologie largamente usate nel settore, una di tipo passivo (Permeable Reactive Barrier) ed una di tipo attivo (Pump and Treat con Carboni Attivi).At the present day, remediation of polluted groundwater can be performed through various technologies; however, these technologies are often associated with relevant costs (both economic and environmental) and technical issues which in some cases may affect the cost effectiveness and feasibility of remediation itself. This is why efforts in the field of research are being increasingly focused in the developement of bioremediation technologies which use the degrading potential of bacteria and microorganism to remove target pollutants. These technologies require a smaller demand for resources and technical equipment in order to achieve clean up targets compared to traditional systems.
The aim of my research work is to provide an assessment of the environmental performance trough LCA methodology of an innovative bioremediation technology (BEARD) and two widespread remediation technologies, a Permeable Reactive Barrier (passive technology) and a Pump and treat system (active technology)
Screening for eating disorders: false negatives and eating disorders not otherwise specified
OBJECTIVE: To study the problem of false negatives in the screening for eating disorders. SUBJECTS AND METHODS: We administered the Eating Attitudes Test (EAT40) and the Eating Disorder Inventory (EDI) to 186 Italian female students (age 17.68 ± 0.9; BMI 20.84 ± 2.69). Then we submitted not only high-scorers but also all the subjects to a semi-structured diagnostic interview (Eating Disorder Examination - EDE 12.0D). The diagnosis of eating disorders not otherwise specified (EDNOS) was applied to cases which met all the DSM-IV criteria for AN and/or BN with one exception. RESULTS: 17 girls (9.1%) fulfilled diagnostic criteria for eating disorders: 1 bulimia nervosa full-syndrome and 16 EDNOS. Of the 17 girls 11 were EAT low-scorers (< 30) and 8 were EDI low-scorers (< 50); 5 subjects scored below the cutoff on both instruments. We calculated sensitivity (35.3%), specificity (88.8%), positive predictive value (PPV, 24.0%) and negative predictive value (NPV, 93.2%) of the EAT40; the respective values for the EDI were 52.9% (sensitivity), 85.2% (specificity), 26.4% (PPV) and 94.7% (NPV). DISCUSSION AND CONCLUSION: Our data show that the introduction of the EDNOS diagnoses increases the PPV of the two questionnaires but lowers their sensitivity. We conclude that using a two stage screening approach leads to a very high rate of false negatives with a significant underestimation of the prevalence of eating disorders, particularly of EDNOS
Executive function impairment in early - treated PKU subjects with normal mental development
Executive functions were studied in 14 early and continuously treated PKU subjects (age 10.8 years, range 8-13) in comparison with controls matched for IQ, sex, age and socioeconomic status. Brain MRI examination was normal in all PKU patients. Neuropsychological evaluation included Wisconsin Card Sorting Test, Rey-Osterreith Complex Figure Test, Elithorn's Perceptual Maze Test, Weigl's Sorting Test, Tower of London, Visual Search and Motor Motor Learning Test. Whatever the IQ, PKU subjects performed worse than controls in tests exploring executive functions. Subgrouping the PKU subjects according to the quality of dietary control for the entire follow-up period (using 400 micromol/L as cut-off value for blood phenylalanine (Phe) concentration) showed that patients with worse dietary control performed more poorly than both the PKU group with the best dietary control and the control group. However, a mild impairment of executive functions was still found in PKU patients with a good dietary control (Phe 400 micromol/L) compared to controls. Concerning the PKU group as a whole, no linear correlation was found between neuropsychological performance and historical and concurrent biochemical parameters. We conclude that (a) PKU patients, even when treated early, rigorously and continuously, show an impairment of frontal lobe functions; (b) a protracted exposure to moderately high levels of Phe can affect frontal lobe functions independently of the possible effect of the same exposure on IQ; (c) in order to reduce the risk of frontal lobe dysfunction, the target of dietary therapy should be to maintain blood Phe concentration below 400 micromol/L
In vitro study of uptake and synthesis of creatine and its precursors by cerebellar granule cells and astrocytes suggests some hypotheses on the physiopathology of the inherited disorders of creatine metabolism
<p>Abstract</p> <p>Background</p> <p>The discovery of the inherited disorders of creatine (Cr) synthesis and transport in the last few years disclosed the importance of blood Cr supply for the normal functioning of the brain. These putatively rare diseases share a common pathogenetic mechanism (the depletion of brain Cr) and similar phenotypes characterized by mental retardation, language disturbances, seizures and movement disorders. In the effort to improve our knowledge on the mechanisms regulating Cr pool inside the nervous tissue, Cr transport and synthesis and related gene transcripts were explored in primary cultures of rat cerebellar granule cells and astrocytes.</p> <p>Methods</p> <p>Cr uptake and synthesis were explored in vitro by incubating monotypic primary cultures of rat type I astrocytes and cerebellar granule cells with: a) D<sub>3</sub>-Creatine (D<sub>3</sub>Cr) and D3Cr plus β-guanidinopropionate (GPA, an inhibitor of Cr transporter), and b) labelled precursors of Guanidinoacetate (GAA) and Cr (Arginine, Arg; Glycine, Gly). Intracellular D3Cr and labelled GAA and Cr were assessed by ESI-MS/MS. Creatine transporter (<it>CT1</it>), L-arginine:glycine amidinotransferase (<it>AGAT</it>), and S-adenosylmethionine:guanidinoacetate N-methyltransferase (<it>GAMT</it>) gene expression was assessed in the same cells by real time PCR.</p> <p>Results</p> <p>D3Cr signal was extremely high in cells incubated with this isotope (labelled/unlabelled Cr ratio reached about 10 and 122, respectively in cerebellar granule cells and astrocytes) and was reduced by GPA. Labelled Arg and Gly were taken up by the cells and incorporated in GAA, whose concentration paralleled that of these precursors both in the extracellular medium and inside the cells (astrocytes). In contrast, the increase of labelled Cr was relatively much more limited since labelled Cr after precursors' supplementation did not exceed 2,7% (cerebellar granule cells) and 21% (astrocytes) of unlabelled Cr. Finally, <it>AGAT, GAMT </it>and <it>SLC6A8 </it>were expressed in both kind of cells.</p> <p>Conclusions</p> <p>Our results confirm that both neurons and astrocytes have the capability to synthesize and uptake Cr, and suggest that at least in vitro intracellular Cr can increase to a much greater extent through uptake than through <it>de novo </it>synthesis. Our results are compatible with the clinical observations that when the Cr transporter is defective, intracellular Cr is absent despite the brain should be able to synthesize it. Further research is needed to fully understand to what extent our results reflect the in vivo situation.</p
The Italian National Register of infants with congenital hypothyroidism: twenty years of surveillance and study of congenital hypothyroidism
All the Italian Centres in charge of screening, diagnosis, and follow-up of infants with congenital hypothyroidism participate in the Italian National Registry of affected infants, which performs the nationwide surveillance of the disease. It was established in 1987 as a program of the Health Ministry and is coordinated by the Istituto Superiore di SanitĂ . The early diagnosis performed by the nationwide newborn screening programme, the prompt treatment and the appropriate clinical management of the patients carried out by the Follow-up Centres, and the surveillance of the disease performed by the National Register of infants with congenital hypothyroidism are the components of an integrated approach to the disease which has been successfully established in our country
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