822 research outputs found

    Correlazione fra stato di salute e concentrazione di vitamina D in un gruppo di soggetti anziani ricoverati in un reparto di Geriatria

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    La vitamina D è da sempre conosciuta come la vitamina che regola il metabolismo osseo, tuttavia studi recenti hanno evidenziato come possa essere piuttosto considerata un ormone con azione pleiotropica su molti organi e tessuti, il cui deficit può essere fattore di rischio per molte malattie come: l’osteoporosi, le fratture, le cadute, le neoplasie, le malattie cardiovascolari, le malattie autoimmuni, le malattie infettive, la BPCO e i deficit cognitivi. La vitamina D potrebbe infatti intervenire sulla patogenesi di queste condizioni croniche attraverso i suoi recettori che sono distribuiti su quasi tutti i tessuti del corpo e quindi la sua azione non si limiterebbe ad effetti calciotropici ma anche non calciotropici per via autocrina e paracrina. Lo scopo della presente tesi è stato quello di valutare l’entità del deficit di vitamina D all’interno di un gruppo di pazienti ricoverati in un reparto di geriatria e ricercare eventuali associazioni tra il deficit di tale vitamina e il loro stato di salute. Il campione esaminato mostra che i soggetti anziani deficitari di vitamina D sono soggetti affetti da più patologie croniche in particolar modo di natura cardiovascolare, con un peggior equilibrio e quindi a maggior rischio di caduta e con una peggior salute somatica valutata tramite la scala di comorbilità CIRS. È quindi molto importante prestare attenzione alla prevenzione del deficit di vitamina D, in particolar modo negli anziani, tenendo conto del favorevole rapporto costi/benefici e del tranquillizzante profilo di sicurezza

    Exogenous phospholipids specifically affect transmembrane potential of brain mitochondria and cytochrome C release.

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    Release of cytochrome c, a decrease of membrane potential (Deltapsi(m)), and a reduction of cardiolipin (CL) of rat brain mitochondria occurred upon incubation in the absence of respiratory substrates. Since CL is critical for mitochondrial functioning, CL enrichment of mitochondria was achieved by fusion with CL liposomes. Fusion was triggered by potassium phosphate at concentrations producing mitochondrial permeability transition pore opening but not cytochrome c release, which was observed only at10 mm. Cyclosporin A inhibited phosphate-induced CL fusion, whereas Pronase pretreatment of mitochondria abolished it, suggesting that mitochondrial permeability transition pore and protein(s) are involved in the fusion process. Phosphate-dependent fusion was enhanced in respiratory state 3 and influenced by phospholipid classes in the order CLphosphatidylglycerol (PG)phosphatidylserine. The probe 10-nonylacridine orange indicated that fused CL had migrated to the inner mitochondrial membrane. In state 3, CL enrichment of mitochondria resulted in a pH decrease in the intermembrane space. Cytofluorimetric analysis of mitochondria stained with 3,3'-diexyloxacarbocyanine iodide and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzymidazolylcarbocyanine iodide showed Deltapsi(m) increase upon fusion with CL or PG. In contrast, phosphatidylserine fusion required Deltapsi(m) consumption, suggesting that Deltapsi(m) is the driving force in mitochondrial phospholipid importation. Moreover, enrichment with CL and PG brought the low energy mitochondrial population to high Deltapsi(m) values and prevented phosphate-dependent cytochrome c release

    Close binary stars modeled by two prolate ellipsoids in synchronous rotation

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    The presence of tidal deformations in close binary stars has already been confirmed by astronomical observations. The present paper aims to simply address an astronomy problem, studying the relative movement of close binaries disturbed by their mutual deformation through some basic concepts and tools of celestial mechanics. For this purpose, the tidal effect is modeled by considering that each star is an elongated revolution ellipsoid in such a way that axes of revolution are coincident, and their largest axes point toward each other along the motion. The potential for mutual attraction is then obtained, resulting in a perturbed Keplerian system with perturbation proportional to the inverse of the cubic distance between the stars, thus being a one-degree-of-freedom problem and, therefore, integrable. The effective potential, the integrals of energy and angular momentum, and the Laplace vector are used to obtain qualitative information about the dynamics before integrating it. The motion describes a rosette-like orbit with periodic osculating elements, or a circle when the energy is a local minimum. Finally, an analytical solution is presented in terms of elliptic functions by using a regularizing and linearizing function

    Assessment of the Triage System in a Pediatric Emergency Department. A pilot study on critical code

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    Introduction. In Italy, triage involves assigning a priority color code to patients arriving at the hospital Emergency Department: red (very critical), yellow (moderately critical), green (not very critical), and white (not critical). Methods. This study was aimed at assessing the triage system in the Emergency Department of ?Giannina Gaslini? Children? s Hospital in Genoa, Italy. The authors examined 130 triage forms assigning a yellow code in 2003, in order to determine whether they had been correctly filled in with regard to the detection of vital parameters, identification of main symptoms and color code assignment. Results. Results showed that vital signs were recorded in 94% of patients, main symptoms were identified in 97%, and a yel- low code was assigned according to hospital guidelines in 84%. The percentage of underestimation (3.2%) was higher than that reported in the literature (2%). Conclusions. The study shows the need to improve compliance with the guidelines and to evaluate green and white codes

    Return visits to the Paediatric Emergency Department: first analysis in Italy

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    Return visits to the emergency room have come under scrutiny with a view to identifying the reasons for these events. The aim of the study was to estimate the incidence of return visits to emer- gency room and to compare this with data from other countries, with a view to proposing a method of monitoring this parameter nationwide. Ours is the first Italian study to report the incidence of return visits to the ER and to analyse the factors correlated with this phenomenon. The incidence of return visits within 72 hours of the first visit proved to be 2.5%. Statistical analysis revealed a significant difference in the number of return visits between patients under 1 year of age and those older than 1 year. Our future objective is to re-analyse recent case-records on the basis of the indicators identified, with a view to assessing the quality of the service

    Heat Conduction and Microconvection in Nanofluids: Comparison between Theoretical Models and Experimental Results

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    A nanofluid is a suspension consisting of a uniform distribution of nanoparticles in a base fluid, generally a liquid. Nanofluid can be used as a working fluid in heat exchangers to dissipate heat in the automotive, solar, aviation, aerospace industries. There are numerous physical phenomena that affect heat conduction in nanofluids: clusters, the formation of adsorbate nanolayers, scattering of phonons at the solid–liquid interface, Brownian motion of the base fluid and thermophoresis in the nanofluids. The predominance of one physical phenomenon over another depends on various parameters, such as temperature, size and volume fraction of the nanoparticles. Therefore, it is very difficult to develop a theoretical model for estimating the effective thermal conductivity of nanofluids that considers all these phenomena and is accurate for each value of the influencing parameters. The aim of this study is to promote a way to find the conditions (temperature, volume fraction) under which certain phenomena prevail over others in order to obtain a quantitative tool for the selection of the theoretical model to be used. For this purpose, two sets (SET-I, SET-II) of experimental data were analyzed; one was obtained from the literature, and the other was obtained through experimental tests. Different theoretical models, each considering some physical phenomena and neglecting others, were used to explain the experimental results. The results of the paper show that clusters, the formation of the adsorbate nanolayer and the scattering of phonons at the solid–liquid interface are the main phenomena to be considered when ϕ = 1 ÷ 3%. Instead, at a temperature of 50 ◦C and in the volume fraction range (0.04–0.22%), microconvection prevails over other phenomen
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