924 research outputs found

    The transport of nanoparticles in blood vessels: the effect of vessel permeability and blood rheology

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    The longitudinal transport of nanoparticles in blood vessels has been analyzed with blood described as a Casson fluid. Starting from the celebrated Taylor and Aris theory, an explicit expression has been derived for the effective longitudinal diffusion (Deff) depending non-linearly on the rheological parameter xi(c), the ratio between the plug and the vessel radii; and on the permeability parameters pi and omega, related to the hydraulic conductivity and pressure drop across the vessel wall, respectively. An increase of xi(c) or pi has the effect of reducing Deff, and thus both the rheology of blood and the permeability of the vessels may constitute a physiological barrier to the intravascular delivery of nanoparticles

    Efficacy and safety of rosuvastatin in the management of dyslipidemia

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    Rosuvastatin is a synthetic statin that represents an advance in the pharmacologic and clinical properties of statins. Relative to other statins, rosuvastatin possesses a greater number of binding interactions with HMG-CoA reductase and has a high affinity for the active site of the enzyme. As with other statins, serious adverse effects with rosuvastatin therapy are uncommon and primarily involve effects on the liver and skeletal muscle. The risk increases with increasing dosages and coadministration with other drugs interacting with the same metabolic pathway. The degree of LDL reduction is important to achieve the treatment goals suggested by international guidelines. Among the most potent statins, rosuvastatin is capable of getting the majority of patients to their LDL cholesterol goals. In addition, rosuvastatin has been found effective in reducing small-dense LDL, C-reactive protein and in increasing HDL cholesterol levels. Controlled clinical trials using vascular end-points have been performed. In particular, a study demonstrated that rosuvastatin therapy could slow progression and/or cause regression of carotid intima-media thickness over 2 years in middle-aged individuals with a low Framingham risk score (FRS) and mild to moderate subclinical atherosclerosis. A primary prevention study (JUPITER) was stopped before the programmed end of the study, because of excess benefit for high-risk individuals receiving rosuvastatin treatment. It is suggested that pronounced LDL reduction, in association with significant HDL cholesterol increase, are the bases of a marked preventive action of rosuvastatin. The results from JUPITER support the use of rosuvastatin for primary cardiovascular prevention, in overweight men and women, with near to normal LDL cholesterol and high CRP. There is now evidence of benefit from rosuvastatin treatment for a wide segment of the general population at intermediate cardiovascular risk. In absolute numbers, this segment represents the main source of cardiovascular events: on the basis of JUPITER results, it is expected that treatment target and potential candidates to statin therapy will be revaluated and redefined

    Metodologia di rilievo della rugosità superficiale del suolo con Pole Aerial Photography (PAP)

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    La valutazione della rugosità superficiale del suolo è importante in agricoltura sotto molteplici aspetti: nello studio delle relazioni tra le rugosità della superficie e volume massimo di stoccaggio di acqua nelle depressioni della superficie per lo sviluppo di modelli idrologici da utilizzare nelle strategie di conservazione del suolo e dell'acqua; ogni qualvolta occorra definire lo stato di amminutamento delle zolle determinato dagli strumenti agricoli di lavorazione del suolo in relazione all'umidità e alle caratteristiche fisiche del suolo. Lo scopo di questo lavoro è stato quello di calibrare una nuova metodologia di misura della Rugosità Superficiale del Suolo (Random Roughness), basata sull'analisi di immagini stereoscopiche ricavate con Metodologia PAP (Pole Aerial Photography). La nuova metodologia si pone due obbiettivi innovativi fondamentali: misurare la Rugosità superficiale su ampie aree campionarie, al fine di una migliore rappresentazione delle superfici; ricavare i valori di rugosità con una tecnologia speditiva a basso costo.</p

    The stable set polytope of claw-free graphs with stability number at least four. I. Fuzzy antihat graphs are W-perfect

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    Abstract Fuzzy antihat graphs are graphs obtained as 2-clique-bond compositions of fuzzy line graphs with three different types of three-cliqued graphs. By the decomposition theorem of Chudnovsky and Seymour [2] , fuzzy antihat graphs form a large subclass of claw-free, not quasi-line graphs with stability number at least four and with no 1-joins. A graph is W -perfect if its stable set polytope is described by: nonnegativity, rank, and lifted 5-wheel inequalities. By exploiting the polyhedral properties of the 2-clique-bond composition, we prove that fuzzy antihat graphs are W -perfect and we move a crucial step towards the solution of the longstanding open question of finding an explicit linear description of the stable set polytope of claw-free graphs

    Eletriptan in the management of acute migraine. An update on the evidence for efficacy, safety, and consistent response

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    Migraine is a multifactorial, neurological and disabling disorder, also characterized by several autonomic symptoms. Triptans, selective serotonin 5-HT1B/1D agonists, are the first-line treatment option for moderate-to-severe headache attacks. In this paper, we review the recent data on eletriptan clinical efficacy, safety, and tolerability, and potential clinically relevant interactions with other drugs. Among triptans, eletriptan shows a consistent and significant clinical efficacy and a good tolerability profile in the treatment of migraine, especially for patients with cardiovascular risk factors without coronary artery disease. It shows the most favorable clinical response, together with sumatriptan injections, zolmitriptan and rizatriptan. Additionally, eletriptan shows the most complex pharmacokinetic/dynamic profile compared with the other triptans. It is metabolized primarily by the CYP3A4 hepatic enzyme and therefore the concomitant administration of CYP3A4-potent inhibitors should be carefully evaluated. A relatively low risk of serotonin syndrome is given by the co-administration with serotoninergic drugs. No clinically relevant interaction has been found with drugs used for migraine prophylactic treatment or other acute drugs, with the exception of ergot derivatives that should not be co-administered with eletriptan

    Gene variants with suicidal risk in a sample of subjects with chronic migraine and affective temperamental dysregulation

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    BACKGROUND: Risk factors for suicide are at least partially heritable and functional polymorphisms of targeted genes have been suggested to be implicated in the pathogenesis of this phenomenon. However, other studies examining the association between specific gene variants and suicide revealed inconsistent findings. We aims to evaluate the possible association between MAO-A3, CYP1A2*1F and GNB3 gene variants, hopelessness and suicidal risk in a sample of subjects with chronic migraine and affective temperamental dysregulation. METHODS: 56 women were genotyped for MAO-A3, CYP1A2*1F and GNB3 gene variants. Participants were also assessed using Beck Hopelessness Scale (BHS), the Temperament Evaluation of the Memphis, Pisa, Paris and San Diego-Autoquestionnaire (TEMPS-A), and the Suicidal History Self-Rating Screening Scale (SHSS). RESULTS: Patients with higher total scores on affective dysregulated temperaments are more likely to have higher BHS (11.27 +/- 5.54 vs. 5.73 +/- 3.81; t19.20 = -3.57; p = 9 indicating high levels of hopelessness. No association was found between MAO-A3, CYP1A2*1F and GNB3 gene variants and suicidal risk as assessed by BHS and SHSS. CONCLUSIONS: This study did not sustain the association between MAO-A3, CYP1A2*1F and GNB3 gene variants and increased suicidal risk in patients with chronic migraine and affective temperamental dysregulation. Further studies investigating the gene-environment interaction or focusing on other genetic risk factors involved in suicidal behaviour are needed

    Local control of near-field diffusion of infected respiratory cloud in a room by air-blades

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    The respiratory cloud of an infective subject contains droplets of mucosalivary fluid carrying pathogens. As this cloud spreads at a certain distance from the emission point, the droplets accumulate and their volume concentration increases in the room unless dilution, adequate ventilation, or filtration reduce it. A susceptible subject, standing a short distance away can be exposed more easily to the infected respiratory cloud, thus inhaling a higher dose of pathogens than someone breathing the mixed air in the room. A local airflow pattern can be employed to reduce this short-distance risk of inhalation and potential contagion. We present experimental and numerical investigations of a novel device acting as a barrier to airborne pathogen diffusion at a short distance. This portable device generates V-shaped air blades in front of the subjects, shifting the respiratory clouds. The air blades are generated by 12 small fans, three on each side of the cube. The air is sucked into the small plenum inside the device body through the bases. By being positioned obliquely on a meeting table, the device acts as a direct barrier to virus-laden aerosols without any filtration. The experimental tests show that the system can reduce the local concentration of aerosol by 63 to 84% at the respiratory position of a subject sitting at a table in front of an infective person. CFD simulation outputs using the Multiphase Eulerian-Lagrangian model show a good agreement with the experimental results. The validated model will be used to extend the range of investigation to different settings and to perform a parametrical analysis of the main design conditions

    Sustainable finance disclosure regulation insights: Unveiling socially responsible funds performance during COVID‐19 pandemic and Russia–Ukraine war

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    The transition towards a more sustainable financial market demands transparency andtrust from investors, objectives also pursued by the Sustainable Finance DisclosureRegulation (SFDR). Specifically, carefully assessing the risk-adjusted performance ofsustainable funds empowers investors to make informed decisions in alignment withtheir ethical and financial objectives. This article contributes to the debate on the per-formance of socially responsible investment (SRI) funds in times of crisis by evaluatingthe risk-adjusted performance of a sample of SRI and conventional funds, ranked inlight of the SFDR, during the COVID-19 pandemic and the Russia–Ukraine war. Usinga two-step analysis, the results of the study show that funds with clear sustainabilityobjectives, as defined by Article 9 of the SFDR, were able to outperform conventionalfunds, but only a few months after the onset of the crisis periods, thus demonstratingpoor performance persistence. At the same time, sustainable funds with a focus onfinancial materiality, as defined by Article 8, were never able to generate significantlydifferent risk-adjusted performance from conventional funds. Our results show thatthe lack of performance persistence of Article 9 funds prevents an effective hedgingrole for investment strategies that consider extra-financial criteria. They also confirmthat the classification criteria introduced by the SFDR still need to be more specificand create more transparency in financial market

    Metaphors: metaphors and the philosophy of language

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    In this dissertation I defend a non-indexicalist contextualist account of metaphorical interpretation. This theory, which works within Kaplan’s double-index semantic framework, claims that context does not have the only role of determining the content expressed by an utterance, but also the function of fixing the appropriate circumstance of evaluation relative to which that content is evaluated. My claim is that the metaphorical dimension of an utterance can be found in the circumstance of evaluation, and not in the content which is expressed by the utterance. To that effect, I introduce a parameter in the circumstance of evaluation of an utterance, which I call ‘thematic dimension’. I show how the introduction of this parameter is in harmony with a class of theories that have proposed a relativistic semantic treatment of other phenomena such as predicates of taste and knowledge ascriptions. At the same time, I question a number of other proposals, both semantic and pragmatic, which, I believe, do not reach the same level of empirical adequacy and formal correctness as my proposal

    Impact of multiple radar reflectivity data assimilation on the numerical simulation of a flash flood event during the HyMeX campaign

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    An analysis to evaluate the impact of multiple radar reflectivity data with a three-dimensional variational (3-D-Var) assimilation system on a heavy precipitation event is presented. The main goal is to build a regionally tuned numerical prediction model and a decision-support system for environmental civil protection services and demonstrate it in the central Italian regions, distinguishing which type of observations, conventional and not (or a combination of them), is more effective in improving the accuracy of the forecasted rainfall. In that respect, during the first special observation period (SOP1) of HyMeX (Hydrological cycle in the Mediterranean Experiment) campaign several intensive observing periods (IOPs) were launched and nine of which occurred in Italy. Among them, IOP4 is chosen for this study because of its low predictability regarding the exact location and amount of precipitation. This event hit central Italy on 14 September 2012 producing heavy precipitation and causing several cases of damage to buildings, infrastructure, and roads. Reflectivity data taken from three C-band Doppler radars running operationally during the event are assimilated using the 3-D-Var technique to improve high-resolution initial conditions. In order to evaluate the impact of the assimilation procedure at different horizontal resolutions and to assess the impact of assimilating reflectivity data from multiple radars, several experiments using the Weather Research and Forecasting (WRF) model are performed. Finally, traditional verification scores such as accuracy, equitable threat score, false alarm ratio, and frequency bias - interpreted by analysing their uncertainty through bootstrap confidence intervals (CIs) - are used to objectively compare the experiments, using rain gauge data as a benchmark
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