1,721,159 research outputs found
The "three-day" rule in upper digestive endoscopy. A prospective controlled study [L’urgenza differita in endoscopia digestiva. Risultati di uno studio prospettico controllato della durata di 12 mesi]
No full textA new initiative, called the Three-Day Rule (TDR), has been introduced in Lombardy in order to promote earlier diagnosis and treatment of severe diseases. It is expected that patients with symptoms/clinical be seen by a specialist or have a diagnostic procedure done within 3 working days of referral by General Practitioners (GPs). We aimed at assessing the effectiveness and compliance with TDR for upper digestive endoscopy (UDE). A prospective audit of all referrals for upper retro intestinal (GI) symptoms under the TDR initiative was done over a 12-month period at a single teaching hospital. We collected demographic data, clinical details, referral cards and final diagnoses on all patients referred for UDE by means of TDR as well as on all outpatients undergoing UDE on open access (OA)-basis during the same period. The appropriateness of the indications for each request was also reviewed. One hundred forty two patients were referred for UDE under the TDR scheme as compared with 767 patients on OA-basis. Six percent had a final diagnosis of oesophageal/gastric cancer in the TDR group as compared to only 1% in the OA-group (p<0.01). Significantly more patients referred by TDR had serious upper GI lesions in comparison with those referred on OA (p<0.05). Thirty nine percent of UDE were rated as inappropriate in the OA-group as compared with 22% in the TDR-group (p<0.01). The TDR-scheme appears to expedite the diagnosis of serious upper GI diseases. However, some GPs appear to over read alarm symptoms, and this may lead to inappropriate referrals. Better awareness of appropriate urgent referral criteria is needed in order to ensure that resources for this initiative are used efficiently
The 13C-urea breath test for non-invasive diagnosis of Helicobacter pylori infection : which procedure and which measuring equipment?
No full text1) The (13)C-urea breath test is one of the most important non-invasive methods for detecting Helicobacter pylori infection in both pre- and post-treatment phases. 2) In order to render the test less expensive and more rapid, a series of modifications have recently been proposed concerning the dose of (13)C-urea and its formulation, as well as the type of measuring equipment used for detecting (13)CO(2) in breath samples. 3) The use of small doses (40--50 mg) of isotope in gelatin capsules or mixed with citric acid in rapid-releasing tablets seems to be promising as it shortens sampling time to 10--20 min. 4) Infrared spectroscopy and laser-assisted ratio analysis equipment are two new valid and less expensive alternatives to conventional isotope mass spectrometry for (13)C analysis in breath.The (13)C-urea breath test is one of the most accurate non-invasive tests for diagnosing Helicobacter pylori infection. This method has become increasingly popular in the last decade since it employs an innocuous, non-radioactive isotope that can be safely used in both children and adults. The test has been recently simplified by reducing the dose of (13)C-urea used, by adopting shorter sampling times and by using new and cheaper measuring methods for (13)C analysis in the breath samples. These include nondispersive isotope-selective infrared spectroscopy (NDIRS) and laser-assisted ratio analysis (LARA), which greatly differ from each other in their technical characteristics and cost. Both NDIRS and LARA are valid alternatives to conventional isotope ratio mass spectrometry (IRMS), although LARA appears to be more suitable for large laboratories or gastroenterological centres, which need to process many breath samples per day, whereas NDIRS seems to be more suitable for small laboratories or doctors' offices
Numerical models for 2D free boundary analysis of groundwater in slopes stabilized by drain trenches.
No full textA numerical model for 2D free boundary analysis of groundwater in slopes stabilized by drain trenches has been developed. It consists of a fronttracking method (based on an original way of adapting the space derivatives), very effective in saving calculation time respect to classical fix-grid methods. The method analyses the trenches effect inside slopes in which the soils above the water table are partially saturated, for which a boundary
can be recognized between the saturated domain (water table) and the unsaturated one (above the water table). In this case pore pressure lowering, due to trenches, can be analyzed considering the progressively reduction of the saturated domain. This approach efficiently solves the problem of fixing hydraulic boundary conditions on the sides of the trenches. Results have been compared with those obtained by a fix-grid method, observing difference less than 0.14%. Applying the method, the capability of drain trenches to control the effect of heavy rainfalls has been investigated, calculating (during the transient process of water table lowering) limit values of water recharge for which water table keeps on constant
Modellazione delle cinetiche di inattivazione cellulare
No full textIn questo capitolo vengono discusse le dinamiche di abbattimento della carica cellulare in seguito all'applicazione di trattamenti termici o di condizioni comunque in grado di procurare danni letali alle cellule di microorganismi di interesse alimentare. In particolare, attraverso la discussione critica delle cinetiche di abbattimento di primo ordine, su cui sono basate le decisioni operative di gran parte dell'industria alimentare, si passa alla descrizione dei modelli alternativi più diffusi, nati per spiegare la presenza di "spalle" o "code" nelle cinetiche di morte cellulare, come il modelli di Weibull, le equazioni di Gompertz e Baranyi applicate all’analisi della disattivazione cellulare, i modelli bifasici e i modelli lognormali. In questo capitolo è anche discussa la modellazione secondaria a partire dai parametri primari e la possibilità di costruire modelli in grado di descrivere l’andamento dell’abbattimento cellulare in condizioni non isotermiche. L’ultima parte del capitolo è riservata alla descrizione dei fenomeni di inattivazione, cioè della perdita di vitalità cellulare determinata dall’esposizione prolungata a fattori ambientali stressanti, e all’abbattimento del numero di cellula attraverso l’applicazione di trattamenti stabilizzanti non termic
Modelli terziari: software e database per la microbiologia predittiva
No full textNel corso degli ultimi 30 anni è stata sviluppata una panoplia di strumenti software on-line e stand-alone che possono assistere ricercatori, operatori dell'industria alimentare e funzionari di agenzie governative nell'applicazione della microbiologia predittiva alla valutazione della sicurezza e qualità degli alimenti, oltre che nella messa a punto di processi e prodotti. Gli strumenti principali possono essere classificati in tre gruppi: database (tramite i quali è possibile accedere a dati grezzi e strutturati sulla crescita e inattivazione di microrganismi), interfacce di modelli (tramite le quali è possibile visualizzare i risultati di modelli primari e secondari per la crescita, inattivazione e sopravvivenza di microrganismi in substrati colturali o matrici alimentari), e strumenti di calcolo (una varietà di applicazioni specifiche per la stima di parametri di curve di crescita o inattivazione, per il calcolo di parametri specifici e per la valutazione del rischio). Alcuni degli strumenti più moderni integrano funzionalità di due o tre di queste categorie e costituiscono dei veri e propri strumenti di supporto alle decisioni. In questo capitolo vengono presentati gli strumenti principali, ne vengono descritte le funzionalità e discusse le limitazioni
Trattamento dell'infezione da Helicobacter pylori resistente a uno o più tentativi di eradicazione
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