46 research outputs found
Measurements of the Complex Conductivity of NbxSi1-x Alloys on the Insulating Side of the Metal-Insulator Transition
We have conducted temperature and frequency dependent transport measurements
in amorphous Nb_x Si_{1-x} samples in the insulating regime. We find a
temperature dependent dc conductivity consistent with variable range hopping in
a Coulomb glass. The frequency dependent response in the millimeter-wave
frequency range can be described by the expression with the exponent somewhat smaller than one. Our ac
results are not consistent with extant theories for the hopping transport.Comment: 4 pages with 3 figures; published version has a different title from
original (was: "Electrodynamics in a Coulomb glass"
CLINICAL OUTCOMES OF SELF-EXPAMDABLE METALLIC STENTS IN PALLIATION OF MALIGNANT ANASTOMOTIC STRICTURES: A SINGLE CENTER EXPERIENCE
Background: self-expandable metallic stents (SEMS) are employed as the preferred non surgical palliative treatment for gastric outlet obstruction due to malignancies. Metallic stents are often employed to treat malignant anastomotic obstructions after surgicsl interventions as esophagojejunostomy, gastrojejunostomy and esophagogastrojejunostomy. Methods: this case series reports prospectively the clinical outcomes of SEMS in the palliative care of malignant anastomotic strictures caused by the recurrence gastric cancer follwing gastric surgery as oncological curative treatment, in a series of nine consecutive patients, treated between January 2009 and december 2012 in our center. Results: Nine patients (M:F=8:1) were enrolled in the study. The operation was a total gastrectomy with esophagogastrojejunostomy (n=4), subtotal gastrectomy with Bilroth-II reconstruction (n=4), subtotal gastrectomy with Billroth-II reconstruction (n=3), and subtotal gastrectomy with esophagogastrostomy (n=2). The technical success rate was 88,9%, and the clinical success rate was 88.9%. The reostruction of the stent, due to the ingrowth of the tumor, occurred in 1 patient (11,1%) within 1 month after stent placement. the migration of the stent occurred after the placement of a covered stent in 1 patient who underwent a subtotal gastrectomy (with Billroth-II reconstruction). A case o partial stent dislodgement was treated with the placement of a second stent. The median survival period was 180 days (range, 30-240 days) and the median stent patency was 45 days 8range, 30-90 days). Conclusions: Although the number of the patients treated with SEMS results, in this series, almost small to certainly judge the safety and feasibility of SEMS, we believe that the endoscopic insertion of SEMS seems to be a safe, easily feasible, and effective treatment in the palliative care of malignant anastomotic strictures caused by the recurrence of gastric cancer following gastric surgery. The technical and clinical success, and the onset of complications of this procedure are influenced by several factors, such as the type of anastomosis, the technical features of the stent, and the extent of the underlying tumor
A Snapshot on MRSA epidemiology in a neonatal intensive care unit network, Palermo, Italy
Objectives: We performed a 1-year prospective surveillance study on MRSA colonization within the five NICUs of the metropolitan area of Palermo, Italy. The purpose of the study was to assess epidemiology of MRSA in NICU from a network perspective. Methods: Transfer of patients between NICUs during 2014 was traced based on the annual hospital discharge records. In the period February 2014-January 2015, in the NICU B, at the University teaching hospital, nasal swabs from all infants were collected weekly, whereas in the other four NICUs (A, C, D, E) at 4 week-intervals of time. MRSA isolates were submitted to antibiotic susceptibility testing, SCCmec typing, PCR to detect lukS-PV and lukF-PV (lukS/F-PV) genes and the gene encoding the toxic shock syndrome toxin (TSST-1), multilocus variable number tandem repeat fingerprinting (MLVF), and multilocus sequence typing (MLST). Results: In the period under study, 587 nasal swabs were obtained from NICU B, whereas 218, 180, 157, and 95 from NICUs A, C, D, and E, respectively. Two groups of NICUs at high prevalence and low prevalence of MRSA colonization were recognized. Overall, 113 isolates of MRSA were identified from 102 infants. Six MLVF types (A-F) were detected, with type C being subdivided into five subtypes. Five sequence types (STs) were found with ST22-IVa being the most frequent type in all NICUs. All the MRSA molecular subtypes, except for ST1-IVa, were identified in NICU B. Conclusions: Our findings support the need to approach surveillance and infection control in NICU in a network perspective, prioritizing referral healthcare facilities
Non-specific hyperreactivity before and after nasal specific immunotherapy
Background: specific local immunotherapy (SLIT) improves symptom scores for allergic rhinitis during treatment and after its conclusion, as confirmed by non-specific tests. However, the duration of clinical and instrumental improvement after discontinuing SLIT is unknown. Objective: to evaluate the changes in the non-specific reaction time of patients with allergy to Dermatophagoides pteronissinus before and during 3 years of SLIT, and 6, 12, 18, and 24 months after discontinuing SLIT. Material and methods: sixteen patients were diagnosed by clinical history, positive skin test for D. pteronissinus, RAST, nasal provocation test (NPT) specific for D. pteronissinus, NPT with cold water solution. SLIT was administered by nasal spray. Patients were evaluated before, at 6, 12, 24, and 36 months of SLIT, and 6, 12, and 18 months after discontinuing SLIT. At the beginning of SLIT, the allergen concentration used was similar to that used in NPT. Maintenance doses were administered 3 times a week for 1 year and 2 times a week for 2 years. All patients kept a symptom diary. Results: after the first year of SLIT, total nasal resistance (TNR) decreased sharply. TNR then remained constant at the end of the second year and decreased at the end of the third year of treatment. Discontinuation of SLIT did not produce evident variations in average TNR at 6 or 12 months, but 3/16 patients at 6 months and 9/16 patients at 12 months complained of symptomatic deterioration. The most evident deterioration was noted at the 18-month post-SLIT visit, in which TNR values were similar to those recorded at the onset of treatment. Positive response to stimulation and increased TNR were found after SLIT in 8/16 patients at 6 months, 13/16 at 12 months, 12/13 at 18 months, and 7/7 at 24 months. The symptom score indicated the return of symptoms. Twelve months after discontinuing SLIT, the patients complained about increased secretion and itching. The initial non-specific hyperreactivity, which had been present in all patients, was not evident in 68.7% after 3 years of SLIT, but persisted in a milder form in 31.3%. Conclusion: SLIT successfully reduced symptoms of D. pteronissinus sensitivity. Non-specific hyperreactivity was absent at the end of SLIT, but returned by 6 months after discontinuing SLIT. Therefore, SLIT did not maintain the clinical results achieved at the beginning of treatment for more than 12 months
Large-Eddy Simulation of Turbulent Flow in an Unbaffled Stirred Tank Driven by a Rushton Turbine
The turbulent flow fieldgeneratedin an unbaffledstirredtank by a Rushton turbine was computedby large-eddy simulation (LES). The
Smagorinsky model was used to model the unresolved, or sub-grid, scales. A general purpose CFD code was appropriately modified in
order to allow the computation of the sub-gridviscosity andto perform statistics on the computedresults. The numerical predictions were comparedwith the literature results for comparable configurations andwith experimental data obtainedusing particle image velocimetry.
A very goodagreement was foundas regards both time-averagedresolv edfield s andturb ulence quantities.
2004 Elsevier Ltd. All rights reserved
Epidemiological aspects of olfactory dysfunction.
PURPOSE: This study aimed at assessing the most common aetiological factors causing total or partial olfactory deficit and the statistical analysis of some clinical aspects. MATERIALS AND METHODS: 243 patients reporting alfactory dysfunction were enrolled in this STUDY: A case history was drawn up for each patient, and all of them underwent otolaryngology objective examination, including nasal endoscopy, paranasal sinuses CT-scan, and Utrecht method (GITU) based smell indentification test. RESULTS: Upper respiratory viral infections (40.2%), ceanial-facial traumas (39.3%), and rhinosinusal pathologies (6.3%) were the main aetiopathological factors indentified. A relevant number of case were recorded with unknown aetiology (14.2%). In 2 cases, olfactory dysfunction was due to neurological diseases, in 1 case it was due to intoxication and, in another case, it was congenital. The correlation between aetiology, gender, age, symptoms duration and deficit severity was studied. CONCLUSIONS: many different aetiological factors caused the loss or weakening of the sense of smell. They mainly affected olfactory neurosensorial structures and odorant conduction. However, there were many cases of unknown aetiology. Women, over 40 in particular, were the most affected. Anosmia and severe hyposmia were mainly correlated with traumas and viral pathologies
Intranasal immunotherapy with Dermatophagoides extract: in vivo and in vitro results of a double-blind placebo-controlled trial.
Intranasal immunotherapy (IT) has been proposed as a means to induce an effective immunity of the nasal mucosa in patients with allergic rhinitis, avoiding systemic side effects. In the present study 20 individuals with chronic allergic rhinitis, and skin prick test reactive to Dermatophagoides pteronyssinus (DP) only, were randomized and subjected to a three months' double-blind placebo-controlled trial of intranasal IT with DP extract. All patients received also sodium cromoglycate as pre-medication. Before and at the end of the treatment the patients performed specific nasal provocation tests, and samples of serum and nasal secretions were collected to measure total and specific IgE, levels of eosinophil cationic protein (ECP), and mast-cell-derived tryptase. A clinical score was computed by the symptoms indicated by the patients. The clinical score did not change in the two groups after the treatment, whereas a decrease in nasal reactivity was observed. Total IgE increased only in secretions from placebo-treated patients, but were not modified in sera. IgE to DP in sera and nasal secretions did not change significantly. Tryptase levels in nasal secretions decreased in both groups, while ECP was unchanged after IT. Serum ECP levels decreased more in actively treated patients than in the placebo group. The data suggest that changes of IgE and inflammatory mediators may be affected by the use of sodium cromoglycate in both groups, but some parameters change early in different directions in IT- and placebo-treated groups