Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
17
result(s) for
"Proserpio, L"
Sort by:
Development of mirrors made of chemically tempered glass foils for future X-ray telescopes
2015
Thin slumped glass foils are considered good candidates for the realization of future X-ray telescopes with large effective area and high spatial resolution. However, the hot slumping process affects the glass strength, and this can be an issue during the launch of the satellite because of the high kinematical and static loads occurring during that phase. In the present work we have investigated the possible use of Gorilla glass (produced by Corning), a chemical tempered glass that, thanks to its strength characteristics, would be ideal. The un-tempered glass foils were curved by means of an innovative hot slumping technique and subsequently chemically tempered. In this paper we show that the chemical tempering process applied to Gorilla glass foils does not affect the surface micro-roughness of the mirrors. On the other end, the stress introduced by the tempering process causes a reduction in the amplitude of the longitudinal profile errors with a lateral size close to the mirror length. The effect of the overall shape changes in the final resolution performance of the glass mirrors was studied by simulating the glass foils integration with our innovative approach based on glass reinforcing ribs. The preliminary tests performed so far suggest that this approach has the potential to be applied to the X-ray telescopes of the next generation.
Profile reconstruction of grazing-incidence X-ray mirrors from intra-focal X-ray full imaging
2015
The optics of a number of future X-ray telescopes will have very long focal lengths (10 - 20 m), and will consist of a number of nested/stacked thin, grazing-incidence mirrors. The optical quality characterization of a real mirror can be obtained via profile metrology, and the Point Spread Function of the mirror can be derived via one of the standard computation methods. However, in practical cases it can be difficult to access the optical surfaces of densely stacked mirror shells, after they have been assembled, using the widespread metrological tools. For this reason, the assessment of the imaging resolution of a system of mirrors is better obtained via a direct, full-illumination test in X-rays. If the focus cannot be reached, an intra-focus test can be performed, and the image can be compared with the simulation results based on the metrology, if available. However, until today no quantitative information was extracted from a full-illumination, intra-focal exposure. In this work we show that, if the detector is located at an optimal distance from the mirror, the intensity variations of the intra-focal, full-illumination image in single reflection can be used to reconstruct the profile of the mirror surface, without the need of a wavefront sensor. The Point Spread Function can be subsequently computed from the reconstructed mirror shape. We show the application of this method to an intra-focal (8 m distance from mirror) test performed at PANTER on an optical module prototype made of hot-slumped glass foils with a 20 m focal length, from which we could derive an expected imaging quality near 16 arcsec HEW.
Evaluation of the surface strength of glass plates shaped by hot slumping process
2014
The Hot Slumping Technology is under development by several research groups in the world for the realization of grazing-incidence segmented mirrors for X-ray astronomy, based on thin glass plates shaped over a mould at temperatures above the transformation point. The performed thermal cycle and related operations might have effects on the strength characteristics of the glass, with consequences on the structural design of the elemental optical modules and consecutively on the entire X-ray optic for large astronomical missions like IXO and ATHENA. The mechanical strength of glass plates after they underwent the slumping process was tested through destructive double-ring tests in the context of a study performed by the Astronomical Observatory of Brera with the collaboration of Stazione Sperimentale del Vetro and BCV Progetti. The entire study has been realized on more than 200 D263 Schott borosilicate glass specimens of dimension 100 mm x 100 mm and thickness 0.4 mm, either flat or bent at a Radius of Curvature of 1000 mm through the particular pressure assisted hot slumping process developed by INAF-OAB. The collected experimental data have been compared to non-linear FEM analyses and treated with Weibull statistic to assess the current IXO glass X-ray telescope design, in terms of survival probability, when subject to static and acoustic loads characteristic of the launch phase. The paper describes the activities performed and presents the obtained results.
A wide field X-ray telescope for astronomical survey purposes: from theory to practice
2010
X-ray mirrors are usually built in the Wolter I (paraboloid-hyperboloid) configuration. This design exhibits no spherical aberration on-axis but suffers from field curvature, coma and astigmatism, therefore the angular resolution degrades rapidly with increasing off-axis angles. Different mirror designs exist in which the primary and secondary mirror profiles are expanded as a power series in order to increase the angular resolution at large off-axis positions, at the expanses of the on-axis performances. Here we present the design and global trade off study of an X-ray mirror systems based on polynomial optics in view of the Wide Field X-ray Telescope (WFXT) mission. WFXT aims at performing an extended cosmological survey in the soft X-ray band with unprecedented flux sensitivity. To achieve these goals the angular resolution required for the mission is very demanding ~5 arcsec mean resolution across a 1-deg field of view. In addition an effective area of 5-9000 cm^2 at 1 keV is needed.
Mapping Rora expression in resting and activated CD4+ T cells
by
Proserpio, Valentina
,
Kar, Gozde
,
Chen, Xi
in
Analysis
,
Animals
,
Antigens, Helminth - immunology
2021
The transcription factor Rora has been shown to be important for the development of ILC2 and the regulation of ILC3, macrophages and Treg cells. Here we investigate the role of Rora across CD4+ T cells in general, but with an emphasis on Th2 cells, both in vitro as well as in the context of several in vivo type 2 infection models. We dissect the function of Rora using overexpression and a CD4-conditional Rora- knockout mouse, as well as a RORA-reporter mouse. We establish the importance of Rora in CD4+ T cells for controlling lung inflammation induced by Nippostrongylus brasiliensis infection, and have measured the effect on downstream genes using RNA-seq. Using a systematic stimulation screen of CD4+ T cells, coupled with RNA-seq, we identify upstream regulators of Rora , most importantly IL-33 and CCL7. Our data suggest that Rora is a negative regulator of the immune system, possibly through several downstream pathways, and is under control of the local microenvironment.
Journal Article
Hippocampal sleep spindles preceding neocortical sleep onset in humans
by
De Gennaro, L.
,
Massimini, M.
,
Ferrara, M.
in
Action Potentials - physiology
,
Adolescent
,
Biological and medical sciences
2014
The coexistence of regionally dissociated brain activity patterns –with some brain areas being active while other already showing sleep signs– may occur throughout all vigilance states including the transition from wakefulness to sleep and may account for both physiological as well as pathological events. These dissociated electrophysiological states are often characterized by multi-domain cognitive and behavioral impairment such as amnesia for events immediately preceding sleep. By performing simultaneous intracerebral electroencephalographic recordings from hippocampal as well as from distributed neocortical sites in neurosurgical patients, we observed that sleep spindles consistently occurred in the hippocampus several minutes before sleep onset. In addition, hippocampal spindle detections consistently preceded neocortical events, with increasing delays along the cortical antero-posterior axis. Our results support the notion that wakefulness and sleep are not mutually exclusive states, but rather part of a continuum resulting from the complex interaction between diffuse neuromodulatory systems and intrinsic properties of the different thalamocortical modules. This interaction may account for the occurrence of dissociated activity across different brain structures characterizing both physiological and pathological conditions.
•Sleep spindles occur in the hippocampus several minutes before sleep onset.•Hippocampal sleep spindles consistently preceded neocortical events.•Sleep onset is characterized by cortical and subcortical dissociated EEG activities.
Journal Article
Phenol-Rich Food Acceptability: The Influence of Variations in Sweetness Optima and Sensory-Liking Patterns
2021
The consumption of phenol-rich foods is limited by their prominent bitterness and astringency. This issue has been addressed by adding sweet tastes, which suppress bitterness, but this is not a complete solution since individuals also differ in their preference for sweetness. In this study, we aimed at identifying groups of consumers differing in sweetness optima and sensory-liking patterns. To this end, increasing concentrations of sucrose were added to a chocolate pudding base. This allowed us to (1) investigate if individual differences in sensory responses are associated with different sweet liking optima in a product context, (2) define the psychological and oro-sensory profile of sweet liker phenotypes derived using a product context, and (3) assess if individuals differing in sweet liking optima differ also in consumption and liking of phenol-rich foods and beverages as a function of their sensory properties (e.g., sweeter vs. more bitter and astringent products). Individuals (1208; 58.4% women, 18–69 years) were characterised for demographics, responsiveness to 6-n-propylthiouracil (PROP), personality traits and attitudes toward foods. Three clusters were identified based on correlations between sensory responses (sweetness, bitterness and astringency) and liking of the samples: liking was positively related to sweetness and negatively to bitterness and astringency in High and Moderate Sweet Likers, and the opposite in Inverted U-Shaped. Differences between clusters were found in age, gender and personality. Furthermore, the Inverted-U Shaped cluster was found to have overall healthier food behaviours and preferences, with higher liking and consumption of phenol-rich vegetables and beverages without added sugar. These findings point out the importance of identifying the individual sensory-liking patterns in order to develop more effective strategies to promote the acceptability of healthy phenol-rich foods.
Journal Article
Homcology: home chemotherapy delivery in a simultaneous care project for frail advanced cancer patients
2021
Homcology is a project that represents both an opportunity for patients who may benefit from chemotherapy so far, but present physical and social problems that prevent day-hospital access, and a model of “no-profit” contribution to the Public Health System. Our medical oncology department conducted the project from May 2014 to January 2019. We included frail patients (G-8 < 14), with advanced disease, treated with oral, subcutaneous, or parenteral biological agents, with limitations to day-hospital access, comorbidities, and at least 6-month life expectancy. A multidisciplinary team included three oncologists, four nurses, an anesthetist, a psychologist, and a physiotherapist. Satisfaction was evaluated with FAMCARE scale. A total of 188 patients (median age of 73 years, 38–87) were enrolled. Ninety percent of patients presented with metastatic disease and a median G-8 score of 8.8 (3–13.5). All of them received anticancer treatment and concomitant supportive care; 24 patients received two or more lines of treatment. The median duration of taking care was 175 days (7–1200). A median number of 254 (195–325) nursing and 164 (139–190) medical visits were performed a year, with an average of 1.9 and 1.2 visits a month per patient respectively. The median number of in-line patients was 20 (17–25). Hospitalization occurred in 18% of cases. One-third of them died at home. The others were referred to hospice. Our experience shows that the integration of home cancer treatment and supportive care is effective. Hospitalization rate is lower than data reported in the literature. Results need to be confirmed in prospective pharmacoeconomics studies.
Journal Article
Preoperative or Perioperative Docetaxel, Oxaliplatin, and Capecitabine (GASTRODOC Regimen) in Patients with Locally-Advanced Resectable Gastric Cancer: A Randomized Phase-II Trial
by
Morgagni, Paolo
,
Viganò, Jacopo
,
Rausei, Stefano
in
5-Fluorouracil
,
Abscesses
,
Cancer therapies
2020
Docetaxel associated with oxaliplatin and 5-fluorouracil (FLOT) has been reported as the best perioperative treatment for gastric cancer. However, there is still some debate about the most appropriate number and timing of chemotherapy cycles. In this randomized multicenter phase II study, patients with resectable gastric cancer were staged through laparoscopy and peritoneal lavage cytology, and randomly assigned (1:1) to either four cycles of neoadjuvant chemotherapy (arm A) or two preoperative + two postoperative cycles of docetaxel, oxaliplatin, and capecitabine (DOC) chemotherapy (arm B). The primary endpoint was to assess the percentage of patients receiving all the planned preoperative or perioperative chemotherapeutic cycles. Ninety-one patients were enrolled between September 2010 and August 2016. The treatment was well tolerated in both arms. Thirty-three (71.7%) and 24 (53.3%) patients completed the planned cycles in arms A and B, respectively (p = 0.066), reporting an odds ratio for early interruption of treatment of 0.45 (95% confidence interval (CI): 0.18–1.07). Resection was curative in 39 (88.6%) arm A patients and 35 (83.3%) arm B patients. Five-year progression-free survival (PFS) was 51.2% (95% CI: 34.2–65.8) in arm A and 40.3% (95% CI: 28.9–55.2) in arm B (p = 0.300). Five-year survival was 58.5% (95% CI: 41.3–72.2) and 53.9% (95% CI: 35.5–69.3) (p = 0.883) in arms A and B, respectively. The planned treatment was more frequently completed and was more active, albeit not significantly, in the neoadjuvant arm than in the perioperative group.
Journal Article