278 research outputs found
Garigliano nuclear power plant: seismic evaluation of the turbine building
The Italian Garigliano Nuclear Power Plant (NPP) started its energy production in 1963. At present it is in the decommissioning stage. In order to get a proper management of the radioactive waste that will be produced during the dismantling operations it has been considered convenient to convert the turbine building of the plant into a temporary waste repository. This decision posed a remarkable seismic safety assessment issue. As a matter of fact, the challenge was to extend, in satisfactory safety conditions, the use of an important facility that has reached the end of its designed lifetime and to have this extended use approved by nuclear safety agencies. In this context many tasks have been accomplished, of which the most important are:
(a) a new appraisal of site seismic hazard;
(b) the execution of many investigations and testing on the
construction materials;
(c) the set up of a detailed 3D finite element model including the explicit representation of foundation piles and soil;
(d) consideration of soil structure kinematic and dynamic nteraction effects.
This paper describes the adopted seismic safety assessment criteria which are based on a performance objectives design approach. While performance based design is the approach currently recommended by European Regulations to manage seismic risk and it is fully incorporated in the Italian code for conventional buildings, bridges and plants, NPP are not explicitly considered. Therefore it was necessary to delineate a consistent interpretation of prescribed rules in order to properly select the maximum and operating design earthquakes on one side and corresponding acceptable limit states on the other side. The paper further provides an outline of the numerical analyses carried out, of the main results obtained and of the principal retrofitting actions that will be realized
Circularity Indicators as a Design Tool for Design and Construction Strategies in Architecture
This study addresses the challenges and barriers associated with the implementation of circular economy principles in architectural design and construction practices. It highlights the fragmented knowledge and lack of a unified approach to circular design as a major obstacle hindering the adoption of circularity. The existing frameworks for assessing circularity, such as the Material Circularity Indicator (MCI) protocol and the Level(s) assessment protocol, are applied to two projects with a high degree of deconstruction to understand their applicability in the architectural design process and identify their limitations. The study emphasises the significance of considering structural connectivity and circularity strategies during the concept-design stage, advocating for the incorporation of circularity at various scales beyond the microscale of materials. Furthermore, it emphasises the need for early implementation of Design for Disassembly (DfD) strategies on circularity scoring to enable meaningful comparisons of alternative designs using circularity metrics. The findings reveal the variability of circularity indicators based on the hierarchy of disassembly and highlights an early-stage design approach to deconstruction strategies to achieve circularity in architectural design. Overall, this study upscales the significance of a comprehensive and integrated approach to circularity in architectural design practices
motor cortical inhibition during concurrent action execution and action observation
Abstract Action Execution (AE) and Action Observation (AO) share an extended cortical network of activated areas. During coordinative action these processes also overlap in time, potentially giving rise to behavioral interference effects. The neurophysiological mechanisms subtending the interaction between concurrent AE and AO are substantially unknown. To assess the effect of AO on observer's corticomotor drive, we run one electromyography (EMG) and three Transcranial Magnetic Stimulation (TMS) studies. Participants were requested to maintain a steady hand opening or closing posture while observing the same or a different action (hand opening and closing in the main TMS study). By measuring Cortical Silent Periods (CSP), an index of GABAB-mediated corticospinal inhibitory strength, we show a selective reduction of inhibitory motor drive for mismatching AE-AO pairs. The last two TMS experiments, show that this mismatch is computed according to a muscle-level agonist-antagonist representation. Combined, our results suggest that corticospinal inhibition may be the central neurophysiological mechanism by which one's own motor execution is adapted to the contextual visual cues provided by other's actions
Mitochondrial Content and Hepcidin are Increased in Obese Pregnant Mothers
OBJECTIVE:
Maternal obesity is characterized by systemic low-grade inflammation and oxidative stress (OxS) with the contribution of fetal sex dimorphism. We recently described increased mitochondrial content (mtDNA) in placentas of obese pregnancies. Here, we quantify mtDNA and hepcidin as indexes of OxS and systemic inflammation in the obese maternal circulation.
METHODS:
Forty-one pregnant women were enrolled at elective cesarean section: 16 were normal weight (NW) and 25 were obese (OB). Obese women were further classified according to the presence/absence of maternal gestational diabetes mellitus (GDM); [OB/GDM(-)]: n\u2009=\u200915, [OB/GDM(+)]: n\u2009=\u200910. mtDNA and hepcidin were evaluated in blood (real-time PCR) and plasma (ELISA).
RESULTS:
mtDNA and hepcidin levels were significantly increased in OB/GDM(-) versus NW, significantly correlating with pregestational BMI. Male/female (M/F) ratio was equal in study groups, and overall F-carrying pregnancies showed significantly higher mtDNA and hepcidin levels than M-carrying pregnancies both in obese and normal weight mothers.
CONCLUSIONS:
Our results indicate a potential compensatory mechanism to increased obesity-related OxS and inflammation, indicated by the higher hepcidin levels found in obese mothers. Increased placental mitochondrial biogenesis, due to lipotoxic environment, may account for the greater mtDNA amount released in maternal circulation. This increase is namely related to F-carrying pregnancies, suggesting a gender-specific placental response
Pharmacological modulation of blood-brain barrier increases permeability of doxorubicin into the rat brain.
Anti-miR21 oligonucleotide enhances chemosensitivity of T98G cell line to doxorubicin by inducing apoptosis.
Eroina e asma bronchiale
Il broncospasmo da eroina, di recente individuazione, è di raro riscontro probabilmente perché poco conosciuto
o non adeguatamente indagato. L’eroina, principalmente attraverso un meccanismo di istamino-liberazione,
induce ostruzione bronchiale che appare piĂą grave negli asmatici cronici e negli atopici manifestandosi pochi
minuti dopo l’inalazione della sostanza. Il narcotico può determinare: a) broncospasmo con insufficienza respiratoria
che può richiedere cure intensive con ricorso alla ventilazione meccanica; b) depressione del centro
bulbare del respiro; c) sintomatologia sistemica; d) sindrome da astinenza, che si può presentare poco dopo
la risoluzione dell’episodio acuto. Un rapporto empatico con il paziente può agevolare il percorso diagnostico;
infatti, la sua reticenza a svelare l’abitudine voluttuaria ritarda l’individuazione dell’esposizione alla sostanza.
Ciò può comportare un trattamento terapeutico ritardato, con conseguente aggravamento della condizione
clinica a possibile evoluzione infausta.Bronchospasm caused by inhaled heroin has recently been identified. The condition has been rarely identified
and/or not sufficiently investigated. Through the reaction mediated by histamine, heroin causes a bronchial
obstruction that seems more severe in chronic asthmatic and atopic individuals, immediately after inhalating
the substance. Heroin can reveal: a) bronchospasm with respiratory failure that may require intensive care up
to mechanical ventilation; b) depression of the bulbar center of breath; c) systemic symptoms; d) withdrawal
syndrome that may be evident after an acute clinical event. Even though an empathic relationship between
the patient and the doctor can facilitate the diagnostic process, a lack of early identification of exposure to the
substance, due to the patient’s hesitation to disclose his/her behavior, may cause a delay in the treatment and
a worsening of clinical conditions with unfavourable development
Peripersonal space representation develops independently from visual experience
Our daily-life actions are typically driven by vision. When acting upon an object, we need to represent its visual features (e.g. shape, orientation, etc.) and to map them into our own peripersonal space. But what happens with people who have never had any visual experience? How can they map object features into their own peripersonal space? Do they do it differently from sighted agents? To tackle these questions, we carried out a series of behavioral experiments in sighted and congenitally blind subjects. We took advantage of a spatial alignment effect paradigm, which typically refers to a decrease of reaction times when subjects perform an action (e.g., a reach-To-grasp pantomime) congruent with that afforded by a presented object. To systematically examine peripersonal space mapping, we presented visual or auditory affording objects both within and outside subjects' reach. The results showed that sighted and congenitally blind subjects did not differ in mapping objects into their own peripersonal space. Strikingly, this mapping occurred also when objects were presented outside subjects' reach, but within the peripersonal space of another agent. This suggests that (the lack of) visual experience does not significantly affect the development of both one's own and others' peripersonal space representation
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