389 research outputs found
Proton induced Dark Count Rate degradation in 150-nm CMOS Single-Photon Avalanche Diodes
Proton irradiation effects on a Single-Photon Avalanche Diodes (SPADs) device
manufactured using a 150-nm CMOS process are presented. An irradiation campaign
has been carried out with protons of 20 MeV and 24 MeV on several samples of a
test chip containing SPADs arrays with two different junction layouts. The dark
count rate distributions have been analyzed as a function of the displacement
damage dose. Annealing and cooling have been investigated as possible damage
mitigation approaches. We also discuss, through a space radiation simulation,
the suitability of such devices on several space mission case-studies.Comment: This is an author-created, un-copyedited version of an article
accepted for publication/published in Nuclear Instruments and Methods in
Physics Research Section A. The Version of Record is available online at
https://doi.org/10.1016/j.nima.2019.16272
Reconstructed SPECT images of 177Lu homogeneous cylindrical phantom used for calibration and texture analysis
In a clinical contest, it is common to use dedicated phantoms to perform quality assurance test to check the performance of a SPECT system. Some of these phantoms are also used to calibrate the system for dosimetric evaluation of patients undergoing radiometabolic cancer therapy. In this work, a 3D-OSEM reconstructed Lu-177 SPECT dataset of a homogeneous cylindrical phantom is described. This dataset was acquired to investigate the variation of the SPECT calibration factor, counts convergence, noise and uniformity by varying the number of subsets and iterations. In particular, the dataset is composed of images reconstructed using five different numbers of subsets and sixteen different numbers of iterations, for a total of 80 different configurations. The dataset is suitable for comparison with other reconstruction algorithms (e.g. FBP, MLEM, etc.) and radionuclides (e.g. technetium, yttrium). In regards to the uniformity issue, the same dataset allows the user to perform radiomic investigations on the influence of the border effect on the reconstructed images
CORRELATES TO ABDOMINAL PAIN IN CONSTIPATION PREVALENT IBS PATIENTS
Background and aim: Symptoms of irritable bowel syndrome (IBS) have
been associated to altered motility and sensation. In constipated prevalent-IBS
patients, a clear association between bowel habit and abdominal pain remains
to be established, and it is not known whether factors related to patients daily
life may play a role in symptoms generation.
Our aim was to evaluate the association between abdominal pain, bowel
habit, demographic factors, alimentary/voluptuary habits and colonic transit
in constipated-IBS patients.
Material and methods: 68 patients complaining of chronic constipation were
selected on the basis of the Rome 3 criteria for IBS. Colonic transit time
(CTT) was studied and alimentary attitudes and smoking habit were recorded.
Presence of mild or severe abdominal pain was scored, as well as the prevalent
pain characteristics, defined as diffuse or localized, chronic or acute, with
cramps or gradually distending. Data were analysed by univariate and stepwise
multiple logistic regression analysis was also used to verify the risk association
between pain and all other variables.
Results: 40 patients were classified as constipated and 28 had alternating
evacuation. Constipated patients had a lower scholar degree, consumed more
laxatives, had a longer transit time in the right colon and scored more
chronic pain than alternating ones, but it was not confirmed by multivariate
analysis. When severity of abdominal pain was used as discriminating factor,
a significant number of subjects reporting severe pain were males (16/30 vs
4/38, p<0.01) and smokers (20/30 vs 4/38, p<0.001). Multivariate analysis
confirmed that only smoking was an independent factor associated with severe
abdominal pain (OR 14.3, CI 2â99, p= 0.007).
Conclusions: Abdominal pain is similarly reported by constipated or alternating
IBS patients and it is not associated with colonic transit time
or demographics. Smoking is the only factor constantly and independently
associated to severe abdominal pain. As smoking does not seem likely to
affect colonic transit time we suggest that smoking may act on the visceral
perception in IBS-constipated patients
Evaluation of reflux following sleeve gastrectomy and one anastomosis gastric bypass: 1-year results from a randomized open-label controlled trial
Background: Recent reports have demonstrated that de novo reflux and worsening of pre-existing symptoms occur after SG; concerns are still expressed about the risk of symptomatic biliary reflux gastritis and oesophagitis. The aim of our study was to investigate and compare the rate of postoperative acid and non-acid reflux following Mini-/One anastomosis gastric bypass (MGB/OAGB) and laparoscopic sleeve gastrectomy (LSG). Study design: A prospective randomized open-label, controlled trial registered on clinicaltrial.gov (NCT number: NCT02987673) has been carried out to evaluate esophagogastric junction exposure to reflux in the first year after MGB/OAGB and LSG using high impedance manometry, endoscopy, and a validated questionnaire. Results: A total of 58 individuals were eventually enrolled in this trial and represented the per-protocol population (n = 28 MGB/OAGB, n = 30 LSG). No difference was found between the two groups in terms of demographic characteristics, PAGI-SYM score, acid exposure time percent of the esophagus (AET%), esophagitis, and other HRiM and MII-pH data at baseline. Comparing MII-pH outcomes of the two groups, AET% resulted significantly higher after LSG at 12Â months. Endoscopic findings showed a significant increase of esophagitis â„ B in the LSG group after 1Â year; postoperative esophagitis â„ B resulted also significantly worsened after LSG when compared to MGB/OAGB. Conclusion: Since AET% and rate of esophagitis are significantly higher after LSG when compared to MGB/OAGB, this procedure should be preferred in case of preoperative subclinical reflux or low grade (A) esophagitis
Fiske steps and hysteresis in YBa2Cu3O7 grain boundary Josephson junctions: Structural Information of the barrier by means of a nondestructive approach.
A deep analysis of the current-voltage _I-V_ characteristics of YBa2Cu3O7 grain boundary Josephson junctions _GBJJs_ allows us to go much farther than the usual calculus of the transport parameters. It is possible to construct a structural image of the barrier by an exhaustive and complementary analysis of both transport and electromagnetic parameters obtained from I-V curves. For such an approach, we have chosen the following three representative bicrystalline geometries: 24° _001_ asymmetric, 45° _100_ asymmetric, and 24° _001_ symmetric +45° _100_ asymmetric. The dependence of the product ICRN on the junction normal resistance is of the ICRN â1 type pointing to a SNINS model _S denotes superconductor, I denotes insulator, and N denotes normal metal_ for all our GBJJs. A satisfactory explanation of the discrepancy of the capacitance of the barrier estimated from Fiske resonance positions and hysteresis in the I-V curves needs of such a model. Moreover an estimation of the length of the normal regions adjacent to the crystallographic barrier can be made. This comparative analysis is presented in order to extract interesting information about the particular transport mechanisms involved in these GBJJs
Eosinophilic esophagitis: From pathophysiology to treatment.
Eosinophilic esophagitis (EoE) is a chronic immune disease, characterized by a dense eosinophilic infiltrate in the esophagus, leading to bolus impaction and reflux-like symptoms. Traditionally considered a pediatric disease, the number of adult patients with EoE is continuously increasing, with a relatively higher incidence in western countries. Dysphagia and food impaction represent the main symptoms complained by patients, but gastroesophageal reflux-like symptoms may also be present. Esophageal biopsies are mandatory for the diagnosis of EoE, though clinical manifestations and proton pump inhibitors responsiveness must be taken into consideration. The higher prevalence of EoE in patients suffering from atopic diseases suggests a common background with allergy, however both the etiology and pathophysiology are not completely understood. Elimination diets are considered the first-line therapy in children, but this approach appears less effective in adults patients, who often require steroids; despite medical treatments, EoE is complicated in some cases by esophageal stricture and stenosis, that require additional endoscopic treatments. This review summarizes the evidence on EoE pathophysiology and illustrates the safety and efficacy of the most recent medical and endoscopic treatments
POLYCHLORODIBENZODIOXINS (PCDDs), POLYCHLORODIBENZO-FURANS (PCDFs), AND DIOXIN-LIKE POLYCHLOROBIPHENYLS (DL-PCBs) IN MILK, MOZZARELLA CHEESE, WHEY, AND WHEY CHEESE FROM BUFFALOES RAISED IN THE CAMPANIA REGION
Dioxins (PCDDs and PCDFs) and PCBs are a group of and toxic organo-chlorinated chemicals comprising hundreds of structurally related compounds (congeners) classified as persistent organic pollutants (POPs). It is acknowledged that 17 PCDD and PCDF congeners are of major concern due to their toxicity; 12 PCB congeners are also recognized to express dioxin-like toxicity and are thereby identified as DL-PCBs. Due to their high persistence and lipophilic nature, dioxins and PCBs tend to accumulate in fat and their bio-accumulation through the food chain may pose the risk of causing adverse effects to human health. For the general population, dietary intake is the most important pathway of exposure to the aforesaid environmental contaminants: meat, milk and dairy products, and fish and other seafood products contribute to total daily intake for more than 90 %. To prevent excessive human exposure to dioxins and DL-PCBs, the European Commission established maximum levels for dioxins and the sum of dioxins and DL-PCBs in an array of food components mainly of animal origin (Regulation EC 1881/2006). In this study, dioxins and DL-PCB concentrations were measured in buffalo milk collected from three impounded Campania farms producing milk with different contamination levels. The fate of contaminants in mozzarella cheese, whey, and whey cheese was also investigated. Analyses were carried out by HRGC-HRMS using US EPA Method 1613. The results of this study show the carry-over of the contamination from milk to its dairy products
ACHALASIA TREATMENT IMPROVES SPECIFIC SYMPTOMS AND QUALITY OF LIFE: VALIDATION OF AN ACHALASIA SPECIFIC QUALITY OF LIFE QUESTIONNAIRE
Background and aim:
Therapies for achalasia aim to patientsâ symptom
relief, but they affect patientâs quality of life (QoL), too. An ad hoc question-
naire evaluating both achalasia-related symptoms and disease related QoL is
lacking.
Aim: To validate a disease specific QoL questionnaire in perspectively
evaluated Italian achalasia patients.
Material and methods:
22 consecutive achalasia patients (4 men, age range
19â86 years) were included in the study. At baseline a structured question-
naire was used to evaluate both esophageal symptoms and disease specific
QoL. Questionnaire graded achalasia-related symptoms severity (dysphagia for solids and liquids, food regurgitation, chest pain, nocturnal cough) from 0
to 3, based on their impact on daily activities. Also a disease specific QoL was
evaluated by a self administred questionnaire, the AE-18, that investigated
four domains (physical, psychological and social functioning, and sleep dis-
turbance). Scores for each item range from 1
(âalwaysâ) to 5 (âneverâ); higher
scores corresponding to better quality of life. All patients were questioned
before, 1 and 6 months after a specific t
reatment regimen, that according
to patients clinical status consisted in pneumatic dilation, botulinum toxin
injection or surgical myotomy.
Results:
Patients within each specific treatment groups were the following
(3/22 surgical myotomy, 14/22 pneumatic dilation and 5/22 Botox injections,
respectively. In the table are reported the baseline demographics and achalasia-
related symptomsâ severity and QoL (data are expressed as mean
±
SD) within
each treatments group.
Table 1
Surgery group Dilation group Botox group p
Age at diagnosis
42.3
±
6.5 42.3
±
13 81.8
±
4.8
<
0.001
Age at onset of symptoms
39.3
±
7.5 40.3
±
12.4 80.8
±
5.6
<
0.001
Dysphagia for solids
2.7
±
0.6 2.2
±
0.7 2.2
±
0.5 0.5
Dysphagia for liquids
2.0
±
1.0 2.1
±
0.7 2.2
±
0.5 0.9
Regurgitation of undigested food 1.0
±
1.7 0.7
±
0.8 0.6
±
1.3 0.8
Chest pain
0.7
±
1.1 1.1
±
1.1 1.0
±
1.4 0.8
Nocturnal cough
1.3
±
1.5 1.3
±
1.2 1.0
±
1.4 0.9
AE-18 total score
54
±
14 53
±
12 53
±
11 0.9
At both 1 and 6 months of the follow-up, the severity mean scores of dysphagia
achalasia-related symptoms severity were significantly reduced compared to
baseline (p
<
0.05). Similarly, the AE-18 total score was significantly improved
(p
<
0.001).
Conclusions:
We showed that therapy-induced improvement of achalasia-
related symptoms correlate with a significant improvement of patients quality
of life as assessed by a specific questionnaire
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