6,407 research outputs found
Interpretation of AMS-02 electrons and positrons data
We perform a combined analysis of the recent AMS-02 data on electrons,
positrons, electrons plus positrons and positron fraction, in a self-consistent
framework where we realize a theoretical modeling of all the astrophysical
components that can contribute to the observed fluxes in the whole energy
range. The primary electron contribution is modeled through the sum of an
average flux from distant sources and the fluxes from the local supernova
remnants in the Green catalog. The secondary electron and positron fluxes
originate from interactions on the interstellar medium of primary cosmic rays,
for which we derive a novel determination by using AMS-02 proton and helium
data. Primary positrons and electrons from pulsar wind nebulae in the ATNF
catalog are included and studied in terms of their most significant (while
loosely known) properties and under different assumptions (average contribution
from the whole catalog, single dominant pulsar, a few dominant pulsars). We
obtain a remarkable agreement between our various modeling and the AMS-02 data
for all types of analysis, demonstrating that the whole AMS-02 leptonic data
admit a self-consistent interpretation in terms of astrophysical contributions.Comment: 33 pages, 26 figures and 4 tables, v2: accepted for publication in
JCAP, minor changes relative to v
Reactive oxygen species inhibit the succinate oxidation-supported generation of membrane potential in wheat mitochondria
In order to gain a first insight into the effects of reactive oxygen species (ROS) on plant mitochondria, we studied the effect of the ROS producing system consisting of xanthine plus xanthine oxidase on the rate of membrane potential (ΔΨ) generation due to either succinate or NADH addition to durum wheat mitochondria as monitored by safranin fluorescence. We show that the early ROS production inhibits the succinate-dependent, but not the NADH-dependent, ΔΨ generation and oxygen uptake. This inhibition appears to depend on the impairment of mitochondrial permeability to succinate. It does not involve mitochondrial thiol groups sensitive to either mersalyl or N-ethylmaleimide and might involve both protein residues and/or membrane lipids, as suggested by the mixed nature. We propose that, during oxidative stress, early generation of ROS can affect plant mitochondria by impairing metabolite transport, thus preventing further substrate oxidation, ΔΨ generation and consequent large-scale ROS production. © 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved
Recurrence of gastrointestinal and extra-intestinal symptoms in celiac patients affected by nickel allergic contact mucositis: when proper gluten-free diet is not enough
BACKGROUND AND AIM: Nickel (Ni) is a metal widely present in nature and the prevalence of Ni allergy is increasing. Allergic contact mucositis (MAC) induced by Ni-rich foods is often responsible for IBS-like disorders and it can be diagnosed by means of a Ni oral mucosa patch test (omPT). It has been observed that, after several months of correct gluten-free diet (GFD), many celiac disease (CD) patients show a recrudescence of gastrointestinal and extra-intestinal symptoms, although serological and histological remission has been achieved. This can be due to a Ni load induced by GFD: a greater consumption of Ni-rich foods (e.g. corn) would lead to a consequent intestinal sensitization to Ni in predisposed subjects. Our study aimed to assess the role played by Ni in the recurrence of symptoms in CD subjects after strict GFD.
MATERIAL AND METHODS: Twenty celiac patients (all female, age 23-65 yrs) in serological and histological remission after at least 12 months of GFD have been consecutively included: they all were complaining recurrence gastrointestinal and extra-intestinal symptoms. Subjects with organic gastrointestinal pathologies were excluded. A symptom questionnaire (GSRS modified according to the Salerno Experts' Criteria) has been administered to all patients in 4 stages: T0 (during free diet - active CD); T1 (after 12 months of GFD - CD remission); T2 (during GFD - recurrence of symptoms); T3 (during GFD and after 3 months of low-Ni diet). Ni omPT was performed at T2. Statistical analysis was performed using Wilcoxon signed rank test.
RESULTS: All 20 patients showed positive Ni omPT, with local and/or systemic alterations confirming Ni ACM diagnosis. The analysis obtained by comparing T2-T3 showed p-value <0.01 for: abdominal pain, bloating, swelling, increased number of evacuations, dermatitis, asthenia; p-value values <0.05 for: heartburn, acid regurgitation, borborygmus, flatulence, loose stools, urgent need for defecation, headache. The other variables were statistically not significant.
CONCLUSIONS: Our data suggest that gastrointestinal and extra-intestinal symptoms observed in CD subjects after prolonged and correct GFD may be due to the necessary dietary change and an increased Ni intake. Specifically, these patients developed Ni MAC, diagnosed by specific Ni omPT. We also observed that regression of symptoms may occur after a proper low-Ni diet. We can conclude that GFD may lead to an increased consumption of Ni-rich foods and this could explain the recurrence of apparently gluten-dependent symptoms
A Movement-Tremors Recorder for Patients of Neurodegenerative Diseases
Neurodegenerative diseases such as Alzheimer, Parkinson, motor neuron, and Chorea affect millions of people today. Their effect on the central nervous system causes the loss of brain functions as well as motor disturbances and sometimes cognitive deficits. In such a scenario, the monitoring and evaluation of early symptoms are mandatory for the improvement of the patient's quality of life. Here, the authors describe the development, the laboratory calibration, and the "in-field validation" under the medical supervision of a movement tremors recorder for subjects affected by neurodegenerative diseases. The developed device is based on an array of four accelerometers connected to an embedded development board. This system is able to monitor tremor/movement, accidental falls, and, moreover, it can track the Alzheimer subjects' geographical position. A remote supervisor can collect data from the system through Bluetooth, Wi-Fi, or GSM connections. A data compression algorithm was developed directly on board in order to increase the efficiency of data transmission and reduce power consumptions
Algoritmo de identificación de etiquetas en botellas de vino
Los conceptos de visión artificial abarcan simples detecciones de color y forma, hasta complejos algoritmos que detectan e identifican objetos en ambientes adversos. En este trabajo se presentan los resultados concatenar seis algoritmos para detección e identificación de etiquetas de vino en estanterías. Se presentan la especificidad y sensibilidad del algoritimo.Sociedad Argentina de Informática e Investigación Operativa (SADIO
Algoritmo de identificación de etiquetas en botellas de vino
Los conceptos de visión artificial abarcan simples detecciones de color y forma, hasta complejos algoritmos que detectan e identifican objetos en ambientes adversos. En este trabajo se presentan los resultados concatenar seis algoritmos para detección e identificación de etiquetas de vino en estanterías. Se presentan la especificidad y sensibilidad del algoritimo.Sociedad Argentina de Informática e Investigación Operativa (SADIO
Controversies in Surgical Staging of Endometrial Cancer
Endometrial cancer is the most common gynaecological malignancy and its incidence is increasing. In 1998, international federation of gynaecologists and obstetricians (FIGO) required a change from clinical to surgical staging in endometrial cancer, introducing pelvic and paraaortic lymphadenectomy. This staging requirement raised controversies around the importance of determining nodal status and impact of lymphadenectomy on outcomes. There is agreement about the prognostic value of lymphadenectomy, but its extent, therapeutic value, and benefits in terms of survival are still matter of debate, especially in early stages. Accurate preoperative risk stratification can guide to the appropriate type of surgery by selecting patients who benefit of lymphadenectomy. However, available preoperative and intraoperative investigations are not highly accurate methods to detect lymph nodes and a complete surgical staging remains the most precise method to evaluate extrauterine spread of the disease. Laparotomy has always been considered the standard approach for endometrial cancer surgical staging. Traditional and robotic-assisted laparoscopic techniques seem to provide equivalent results in terms of disease-free survival and overall survival compared to laparotomy. These minimally invasive approaches demonstrated additional benefits as shorter hospital stay, less use of pain killers, lower rate of complications and improved quality of life
Analysis of viral nucleic acids in duodenal biopsies from adult patients with active celiac disease: in search for an etiological relationship
BACKGROUND AND AIM: Celiac Disease (CD) is a multisystemic chronic inflammatory autoimmune disease which develops in genetically predisposed subjects and it is triggered by the ingestion of gluten. After the interaction between HLA-DQ2/DQ8 and gluten-derived peptides, lymphocytes T CD4+ start a specific immune response which ends in a chronic inflammation and mucosal damage. CD pathogenesis is complex and not entirely understood, probably due to an alteration in the gastrointestinal immune system or to its aberrant regulation. Furthermore, many environmental and immune factors could be involved, particularly viral infections. The aim of the study was to observe possible relationships between CD and infections from HHV-6 A/B, EBV, CMV, adenovirus and rotavirus.
MATERIAL AND METHODS: Thirty-nine adult patients (aged 18-65 yrs) have been enrolled: specifically, 24 duodenal biopsies from active CD patients and 15 biopsies from non-CD patients were analyzed. CD diagnosis has been performed by means of serological antibodies, histology of duodenal biopsies and duodenal biopsy organ culture. Viral nucleic acids were extracted from duodenal biopsies and then amplified using Real-Time PCR technique.
RESULTS: HHV-6B was found in 62.5% of CD patients and in 73.3% of non-CD patients (p=0.13). EBV was found in 4.5% of CD patients and 6.7% of non-CD patients (p=0.35). Nucleic acids from HHV-6A, CMV, adenovirus and rotavirus were not detected in any group. HHV-6B viral load in CD patients was higher than in non-CD patients, but data were not statistically significant (p=0.54). CD patients with HHV-6B viral load >50000 copies/ml resulted to be younger and had lower anti-tTG antibody titers found at organ culture than patients with lower HHV-6B viral load (p>0.05).
CONCLUSIONS: There seems to be no difference in viral load and/or in the detection of viruses between CD and non-CD patients. Thus, our data do not support the possible relationship between CD and viral infections, although a larger population is needed to confirm our study results
A26-3 Tip design in a new steroid-elution pacing lead influences ventricular electrical parameter variations in DDD pacemaker implanted patients
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Investigation of the skin contamination predictability by means of QForm UK extrusion code
The paper presents an innovative approach implemented in QForm UK Extrusion FEM software to analyse one of the core defects encountered in profile extrusion known as billet skin defect. The validation of the algorithm has been performed based on a number of experimental case studies taken from the literature [1,2]. Additionally, the sensitivity of the accuracy of the results to the variation in initial parameters has been analysed for both types of profile shapes: solid and hollow. Based on this, practical recommendations have been formalised for the successful industrial use of the presented algorithm
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