440 research outputs found
Appropriate end points for the characterization of behavioral changes in developmental toxicology.
The present paper is devoted to second- and higher-tier test methods for the characterization of behavioral changes produced in rodents by exposure to noxious agents during development. The paper analyzes a series of end points that are informative about specific processes and underlying regulatory mechanisms but require greater technical sophistication and larger investments than first-tier end points. This applies to ultrasonic emissions in successive postnatal periods; to mother-pup interactions, including appropriate cross-fostering controls; to social (including sexual) interaction tests from the infantile to the young adult stage; and to a variety of conditioning and learning tests using both positive and negative reinforcement
FONESYS and SILENCE Networks: Looking to the Future of T-H Code Development and Experimentation
The purpose of this paper is to present briefly the projects called FONESYS (Forum &
Network of System Thermal-Hydraulics Codes in Nuclear Reactor Thermal-Hydraulics) and
SILENCE (Significant Light and Heavy Water Reactor Thermal Hydraulic Experiments
Network for the Consistent Exploitation of the Data), their participants, their motivations,
their main targets and working modalities.
System Thermal-Hydraulics (SYS-TH) codes, also as part of the Best Estimate Plus
Uncertainty (BEPU) approaches, are expected to achieve a more-and-more relevant role in
nuclear reactor safety and design technology. Namely, the number of code-users is likely to
increase in the countries where nuclear technology is exploited. Thus, the idea of establishing
a forum and a network among the code developers and with possible extension to code users
has started to have major importance and value. In this framework, the FONESYS initiative
has been launched in 2010 aiming at creation of a common ground for discussing current
limitations and envisaged improvements in various areas of SYS-TH and their application in
the licensing process and safety analysis.
According to FONESYS statute, there are seven signatory Institutions and two observer
Institutions currently participating in the project. Signatory Institutions are AREVA-NP,
Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA), San Piero a Grado
Nuclear Research Group - University of Pisa (GRNSPG-UNIPI), Gesellschaft fĂĽr Anlagenund
Reaktorsicherheit (GRS), Korea Atomic Energy Research Institute (KAERI), Korea
Institute of Nuclear Safety (KINS), and VTT Technical Research Centre of Finland.
SILENCE is a network that intends to promote the cooperation among teams of
experimentalists managing or involved in significant experimental projects in nuclear reactor
thermal-hydraulics, with the aim to contrast the risk of losing expertise and vision in this
important area of the nuclear technology. This network was launched in 2012, replicating for
the TH experimental domain the role that FONESYS plays in the code-development domain.
Currently, the following Organizations are Members of SILENCE: AREVA GmbH,
Helmholtz Zentrum Dresden-Rossendorf (HZDR), Korea Atomic Energy Research Institute
(KAERI), Hungarian Academy of Sciences Centre for Energy Research (MTA EK),Lappeenranta University of Technology (LUT), and Paul Scherrer Institute (PSI). SILENCE
is currently organizing a “Specialists Workshop on Advanced Instrumentation and
Measurement Techniques for Nuclear Reactor Thermal Hydraulics” (SWINTH-2016).
The San Piero a Grado Nuclear Research Group - University of Pisa (GRNSPG-UNIPI)
is the Host Institution and plays as a Scientific Secretariat for both Networks
The effect of ceramic YSZ powder morphology on coating performance for industrial TBCs
The increasing turbine inlet temperatures in modern gas turbines have raised concerns about the corrosion of ceramic thermal barrier coatings (TBCs) caused by molten silicate deposits, commonly referred to as “CMAS” due to their main constituents (CaO-MgO-Al2O3-SiO2). The objective of this study was to investigate the combined influence of powder morphology and chemical composition on the CMAS resistance and thermal cycling resistance of ceramic monolayer and bi-layer coatings created through Atmospheric Plasma Spraying (APS). Three powder morphologies were examined: porous Agglomerated and Sintered (A&S) granules, Hollow Spherical (HOSP) powders, and dense, irregular Fused and Crushed (F&C) particles. Monolayer 7-8YSZ coatings with both porous and dense vertically cracked (DVC) microstructures, and bi-layer coatings consisting of a bottom layer of porous standard 7-8YSZ and a top layer composed of a porous high‑yttrium ZrO2–55 wt% Y2O3 were obtained using all three powder types (A&S, HOSP, or F&C). Furthermore, the bi-layer systems were deposited with different ratios between the individual layer thicknesses and/or different total thickness. FEG-SEM, EDX, and micro-Raman analyses, were conducted to assess the coatings' performance. Nanoindentation high-speed mapping and pillar splitting test were performed to evaluate the mechanical behaviour. The study on 8YSZ monolayers shows that coatings from a F&C feedstock exhibit higher density, reducing the CMAS penetration. However, these coatings demonstrate poorer thermal cycling performance due to increased stiffness and thermal stresses. Coatings from HOSP and A&S powders allow CMAS penetration but offer stress relief pathways, enhancing the coating's ability to withstand thermal stresses. Bi-layer coatings with a 55YSZ top coat show superior CMAS resistance compared to 7-8YSZ monolayer coatings, with limited penetration causing top coat peeling. The thickness ratio between the layers also affects thermal cycling resistance, where a thinner 55YSZ layer extends the TBC lifetime
A lymphofollicular microenvironment is required for pathological prion protein deposition in chronically inflamed tissues from scrapie-affected sheep
In sheep scrapie, pathological prion protein (PrPSc) deposition occurs in the lymphoreticular and central nervous systems. We investigated PrPSc distribution in scrapie- affected sheep showing simultaneous evidence of chronic lymphofollicular, lymphoproliferative/non-lymphofollicular,and/or granulomatous inflammations in their mammary gland, lung, and ileum. To do this, PrPSc detection was carried out via immunohistochemistry and Western Blotting techniques, as well as through inflammatory cell immunophenotyping. Expression studies of gene coding for biological factors modulating the host’s inflammatory response were also carried out. We demonstrated that ectopic PrPSc deposition occurs exclusively in the context of lymphofollicular inflammatory sites, inside newly formed and well-organized lymphoid follicles harboring follicular dendritic cells. On the contrary, no PrPSc deposition was detected in granulomas, even when they were closely located to newly formed lymphoid follicles. A significantly more consistent expression of lymphotoxin α and β mRNA was detected in lymphofollicular inflammation compared to the other two types, with lymphotoxin α and β signaling new lymphoid follicles’ formation and, likely, the occurrence of ectopic PrPSc deposition inside them. Our findings suggest that, in sheep co-affected by scrapie and chronic inflammatory conditions, only newly formed lymphoid follicles provide a suitable micro-environment that supports the scrapie agent’s replication in inflammatory sites, with an increased risk of prion shedding through body secretions/excretions.[...
Which route of antibiotic administration should be used for third molar surgery? A split-mouth study to compare intramuscular and oral intake
Objectives. To compare the effectiveness of two different routes of antibiotic administration in preventing septic complications in patients undergoing third molar extraction.
Materials and Methods. Twenty-four healthy patients requiring bilateral surgical removal of impacted mandibular third molars were successfully enrolled for this study. Depth of impaction, angulation, and relationship of the lower third molars with the mandibular branch had to be overlapping on both sides. A split-mouth design was chosen, so each patient underwent both the first and second surgeries, having for each extraction a different antibiotic route of administration. The second extraction was carried out 1 month later. To compare the effects of the two routes of antibiotic administration, inflammatory parameters, such as edema, trismus, pain, fever, dysphagia and lymphadenopathy were evaluated 2 and 7 days after surgery. Side effects of each therapy were evaluated 48h after surgery.
Results. oral and intramuscular antibiotic therapies overlap in preventing post-operative complications in dental surgery (p>0.05), even if the oral intake, seems to promote the onset of significant gastrointestinal disorders (p=0.003).
Conclusions. This study could help dentists in their ordinary practice to choose the right route of antibiotic administration in the third molar surgery. At the same effectiveness, the higher cost and the minor compliance of the patient seem not to justify a routine antibiotic intramuscular therapy, reserving it for patients with gastrointestinal disorders
Exploring the role of Fusobacterium nucleatum in preterm birth: A narrative review
In recent years, substantive attention has been drawn to the relationship between oral microbiome homeostatic equilibrium disruption and systemic health, demonstrating the negative impacts of this reciprocal biological interplay. Increasingly, there is a concern over the potential noxious effect of oral microbiome dysbiosis on obstetric poor outcomes, focusing on preterm birth. This epidemiological observation remains unexplained, although biologically plausible mechanism has been proposed. Intrauterine infection has long been associated with adverse pregnancy, when the elicitation of an immune response is determinant. There is evidence that Fusobacterium nucleatum (FN), a Gram-negative anaerobe ubiquitous in the oral cavity, infects the mouse placenta originating in the decidua basalis. Based on the current data in literature, we performed a review to provide resources for the explanation of the potential impact of microbiome dysbiosis on poor obstetric outcomes, focusing on the role of FN
PERIODONTITIS AND EARLY MORTALITY IN ADULTS WITH KIDNEY FAILURE TREATED WITH HEMODIALYSIS: A MULTINATIONAL OBSERVATIONAL STUDY
Introduction and Aims: Periodontitis is associated with cardiovascular mortality in the general population and adults with chronic diseases, however prognostic data for periodontitis in the setting of kidney failure are sparse. The aim of the study was to evaluate whether periodontitis was prognostic for all-cause and cardiovascular-related death in adults with kidney failure.
Methods: ORALD is a multinational cohort study in adults with kidney failure treated with haemodialysis in Europe (France, Hungary, Italy, Poland, Portugal and Spain) and Argentina. Periodontitis was measured at baseline according to the World Health Organization Community Periodontal Index. The outcomes were all-cause and cardiovascular mortality. Analyses were conducted using a fixed-effect Cox proportional hazards analysis and additionally using a random effects model fitted using shared frailty to account for clustering within countries.
Results: Periodontitis was evaluable in 3338 dentate participants of which 1355 (40.6%) had moderate to severe periodontitis. During 6150 person-years of follow-up, 650 deaths occurred of which 325 were cardiovascular. In multivariable analyses, moderate to severe periodontitis was associated with a lower hazard of all-cause (HR 0.76, 95% confidence interval 0.64 to 0.90) and cardiovascular (0.69, 0.54 to 0.87) mortality. There was evidence of decreasing mortality risks with more severe periodontal disease (P≤0.001 for trend). However, when analyses accounted for clustering of participants within countries, the associations between periodontitis and all-cause (0.92, 0.75 to 1.11) and cardiovascular (0.83, 0.63 to 1.09) mortality were not significant. Similar results were observed in analyses restricted to participants with 12 or more teeth and when competing risks for cardiovascular death were considered.
Conclusions: Unlike in the general population, there is limited evidence that periodontitis is independently associated with increased all-cause or cardiovascular mortality in adults with kidney failure
Oral lichen planus clinical characteristics in Italian patients: a retrospective analysis
Main Results of Phase IV BEMUSE Project: Simulation of LBLOCA in an NPP
Phase IV of BEMUSE Program is a necessary step for a subsequent uncertainty analysis. It includes the simulation of the reference
scenario and a sensitivity study. The scenario is a LBLOCA and the reference plant is Zion 1 NPP, a 4 loop PWR unit. Thirteen
participants coming from ten different countries have taken part in the exercise. The BEMUSE (Best Estimate Methods plus
Uncertainty and Sensitivity Evaluation) Programhas been promoted by theWorking Group on AccidentManagement and Analysis
(WGAMA) and endorsed by the Committee on the Safety of Nuclear Installations (CSNI). The paper presents the results of the
calculations performed by participants and emphasizes its usefulness for future uncertainty evaluation, to be performed in next
phase. The objectives of the activity are basically to simulate the LBLOCA reproducing the phenomena associated to the scenario
and also to build a common, well-known, basis for the future comparison of uncertainty evaluation results among different
methodologies and codes. The sensitivity calculations performed by participants are also presented. They allow studying the
influence of different parameters such as material properties or initial and boundary conditions, upon the behaviour of the most
relevant parameters related to the scenario
- …