898 research outputs found

    Structure of a model TiO2 photocatalytic interface

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    The interaction of water with TiO2 is crucial to many of its practical applications, including photocatalytic water splitting. Following the first demonstration of this phenomenon 40 years ago there have been numerous studies of the rutile single-crystal TiO2(110) interface with water. This has provided an atomic-level understanding of the water-TiO2 interaction. However, nearly all of the previous studies of water/TiO2 interfaces involve water in the vapour phase. Here, we explore the interfacial structure between liquid water and a rutile TiO2(110) surface pre-characterized at the atomic level. Scanning tunnelling microscopy and surface X-ray diffraction are used to determine the structure, which is comprised of an ordered array of hydroxyl molecules with molecular water in the second layer. Static and dynamic density functional theory calculations suggest that a possible mechanism for formation of the hydroxyl overlayer involves the mixed adsorption of O2 and H2O on a partially defected surface. The quantitative structural properties derived here provide a basis with which to explore the atomistic properties and hence mechanisms involved in TiO2 photocatalysis

    Beam diagnostics for charge and position measurements in ELI-NP GBS

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    The advanced source of Gamma-ray photons to be built in Bucharest (Romania), as part of the ELI-NP European Research Infrastructure, will generate photons by Compton back-scattering in the collision between a multi-bunch electron beam and a high intensity recirculated laser pulse. An S-Band photoinjector and the following C-band Linac at a maximum energy of 720MeV, under construction by an European consortium (EurogammaS) led by INFN, will operate at 100Hz repetition rate with trains of 32 electron bunches, separated by 16ns and a 250pC nominal charge. The different BPMs and current transformers used to measure transverse beam position and charge along the LINAC are described. Design criteria, production status and bench test results of the charge and position pickups are reported in the paper, together with the related data acquisition systems

    The European Union, borders and conflict transformation: the case of Cyprus

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    Much of the existing literature on the European Union (EU), conflict transformation and border dynamics has been premised on the assumption that the nature of the border determines EU intervention and the consequences that flow from this in terms of EU impact. The article aims to transcend this literature through assessing how domestic interpretations influence EU border transformation in conflict situations, taking Cyprus as a case study. Moreover, the objective is to fuse the literature on EU bordering impact and perceptions of the EU’s normative projection in conflict resolution. Pursuing this line of inquiry is an attempt to depart from the notion of borders being constructed solely by unidirectional EU logics of engagement or bordering practices to a conceptualization of the border as co-constituted space, where the interpretations of the EU’s normative projections by conflict parties, and the strategies that they pursue, can determine the relative openness of the EU border

    Blood pressure control in Italy: analysis of clinical data from 2005-2011 surveys on hypertension

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    Introduction: Blood pressure (BP) control is poorly achieved in hypertensive patients, worldwide. Aim: We evaluated clinic BP levels and the rate of BP control in hypertensive patients included in observational studies and clinical surveys published between 2005 and 2011 in Italy. Methods: We reviewed the medical literature to identify observational studies and clinical surveys on hypertension between January 2005 and June 2011, which clearly reported information on clinic BP levels, rates of BP control, proportions of treated and untreated patients, who were followed in different clinical settings (mostly in general practice, and also in outpatient clinics and hypertension centres). Results: The overall sample included 158 876 hypertensive patients (94 907 women, mean age 56.6 +/- 9.6 years, BMI 27.2 +/- 4.2 kg/m(2), known duration of hypertension 90.2 +/- 12.4 months). In the selected studies, average SBP and DBP levels were 145.7 +/- 15.9 and 87.5 +/- 9.7 mmHg, respectively; BP levels were higher in patients followed in hypertension centres (n = 10 724, 6.7%; 146.5 +/- 17.3/88.5 +/- 10.3 mmHg) than in those followed by general practitioners (n = 148 152, 93.3%; 143.5 +/- 13.9/84.8 +/- 8.9 mmHg; P < 0.01). More than half of the patients were treated (n = 91 318, 57.5%); among treated hypertensive patients, only 31 727 (37.0%) had controlled BP levels. Conclusion: The present analysis confirmed inadequate control of BP in Italy, independently of the clinical setting. Although some improvement was noted compared with a similar analysis performed between 1995 and 2005, these findings highlight the need for a more effective clinical management of hypertension

    Cardiovascular risk assessment beyond Systemic Coronary Risk Estimation: a role for organ damage markers

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    BACKGROUND: Cardiovascular risk assessment in the clinical practice is mostly based on risk charts, such as Framingham risk score and Systemic Coronary Risk Estimation (SCORE). These enable clinicians to estimate the impact of cardiovascular risk factors and assess individual cardiovascular risk profile. Risk charts, however, do not take into account subclinical organ damage, which exerts independent influence on risk and may amplify the estimated risk profile. Inclusion of organ damage markers in the assessment may thus contribute to improve this process. OBJECTIVE: Our aim was to evaluate the influence of implementation of SCORE charts with widely available indexes of organ damage, with the purpose to ameliorate individual risk assessment. METHODOLOGY: We searched www.Pubmed.gov for evidence about the predictive value of left ventricular hypertrophy (LVH), estimated glomerular filtration rate (eGFR), microalbuminuria (MAU) and metabolic syndrome on different risk profiles estimated by SCORE. Interventional and observational trials including at least 200 patients and published after 2000 were selected. RESULTS: The presence of organ damage as well as the number of abnormal parameters indicating organ damage is associated with increased cardiovascular risk, independently of SCORE. In the area of high risk, the impact of different markers of organ damage is heterogeneous. Combined risk models of SCORE and subclinical organ damage have major impact on risk stratification and may impact on recommendation in primary prevention in all SCORE categories. CONCLUSION: Available evidence suggests a tangible clinical advantage of adding the evaluation of simple organ damage markers to risk charts in cardiovascular risk prediction

    PREVALENCE OF 'BORDERLINE' VALUES OF CARDIOVASCULAR RISK FACTORS IN THE CLINICAL PRACTICE OF GENERAL MEDICINE IN ITALY: RESULTS OF THE BORDERLINE STUDY.

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    INTRODUCTION: The prevalence of patients with 'borderline' levels of cardiovascular risk factors has been rarely investigated, being often reported in studies evaluating abnormal values of these parameters. The BORDERLINE study represents a pilot experience to primarily identify the prevalence of 'high-normal' conditions, such as pre-hypertension, lipid and glucose levels in the upper range of normality in the setting of general practice in Italy. AIM: The aim of this study was to evaluate the prevalence of patients with 'borderline' values of cardiovascular risk factors in Italy. METHODS: Involved physicians were asked to evaluate the first 20 outpatients, consecutively seen in June 2009. Data were collected in a study-designed case-report form, in which physicians identified thresholds rather than reported absolute values of several clinical parameters. High-normal values were defined as follows: blood pressure (BP) 130-140/85-90 mmHg; total cholesterol 180-200 mg/dL; low-density lipoprotein cholesterol (LDL-C) 130-150 mg/dL; high-density lipoprotein cholesterol (HDL-C) 30-40 mg/dL in males and 40-50 mg/dL in females; triglycerides 130-150 mg/dL and fasting glucose 100-110 mg/dL. RESULTS: Fifty-three Italian physicians provided valuable clinical data on 826 individual outpatients, among which 692 (83.7%, 377 women, mean age 60.9 ± 13.2 years, body mass index 26.6 ± 5.0 kg/m2) were included in the present analysis. Prevalence of borderline values of systolic BP and total cholesterol levels were at least comparable with those in the normal limits of the corresponding parameters, whereas prevalence of borderline diastolic BP, LDL-C, HDL-C, triglycerides and fasting glucose levels was significantly lower than that of normal values, but higher than that of abnormal values of the corresponding parameters. CONCLUSIONS: Using this sample of healthy subjects in the setting of general practice in Italy, our results demonstrated a relatively high prevalence of borderline values of cardiovascular risk factors, which was at least comparable with that of normal, but significantly higher than that of abnormal thresholds. These preliminary findings may prompt more extensive investigations in the area of 'borderline' cardiovascular risk. This information may, in fact, potentially enable the design of more effective prevention strategies in the future to limit the burden of cardiovascular disease in the general population in Italy

    Blood pressure control in Italy: analysis of clinical data from 2005-2011 surveys on hypertension

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    INTRODUCTION: Blood pressure (BP) control is poorly achieved in hypertensive patients, worldwide. AIM: We evaluated clinic BP levels and the rate of BP control in hypertensive patients included in observational studies and clinical surveys published between 2005 and 2011 in Italy. METHODS: We reviewed the medical literature to identify observational studies and clinical surveys on hypertension between January 2005 and June 2011, which clearly reported information on clinic BP levels, rates of BP control, proportions of treated and untreated patients, who were followed in different clinical settings (mostly in general practice, and also in outpatient clinics and hypertension centres). RESULTS: The overall sample included 158 876 hypertensive patients (94 907 women, mean age 56.6 ± 9.6 years, BMI 27.2 ± 4.2 kg/m(2), known duration of hypertension 90.2 ± 12.4 months). In the selected studies, average SBP and DBP levels were 145.7 ± 15.9 and 87.5 ± 9.7 mmHg, respectively; BP levels were higher in patients followed in hypertension centres (n = 10 724, 6.7%; 146.5 ± 17.3/88.5 ± 10.3 mmHg) than in those followed by general practitioners (n = 148 152, 93.3%; 143.5 ± 13.9/84.8 ± 8.9 mmHg; P < 0.01). More than half of the patients were treated (n = 91 318, 57.5%); among treated hypertensive patients, only 31 727 (37.0%) had controlled BP levels. CONCLUSION: The present analysis confirmed inadequate control of BP in Italy, independently of the clinical setting. Although some improvement was noted compared with a similar analysis performed between 1995 and 2005, these findings highlight the need for a more effective clinical management of hypertension

    Influence of FK 506 (tacrolimus) on circulating CD4 <sup>+</sup> t cells expressing cd25 and cd45ra antigens in 19 patients with chronic progressive multiple sclerosis participating in an open label drug safety trial

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    We have taken the opportunity of a clinical trial of the potential efficacy and safety of FK 506 (tacrolimus) in chronic progressive multiple sclerosis (MS) to examine the influence of this potent new immunosuppressant on circulating T-lymphocytes in an otherwise healthy non-transplant population. Peripheral blood levels of subsets of CD4+ T lymphocytes expressing the activation molecule interleukin-2 receptor (p55 α chain; CD25) or the CD45RA isoform were determined sequentially in 19 patients that were treated continuously with oral FK 506 (starting dose 0.15 mg/kg/day) for 12 months. No significant change in the proportion of circulating CD25 + CD4+ cells was observed over the study period in which the mean trough plasma FK 506 level rose from 0.3 ±0.2 to 0.5 ±0.4 ng/ml. There was also no significant effect of FK 506 on the percentage of CD45RA + CD4 + cells in the peripheral blood at 12 months compared with pretreatment values. Analysis of a subgroup of 7 patients, who showed a sustained reduction in CD25 + CD4+ cells and a reciprocal increase in CD45RA* CD4 * cells for at least 6 months after start of treatment, did not reveal any difference in disability at one year compared with the treatment group as a whole. The side effects of FK 506 were mild and the overall degree of disability estimated by the mean Kurtzke expanded disability status scale (EDSS) score or the ambulation index did not deteriorate significantly in the 19 patients studied over the 12 months of FK 506 administration. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted

    Realistic modelling of water/solid interfaces from ab Initio molecular dynamics

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    Water/solid interfaces are of utmost importance to a number of technological processes. Theoretical studies, based on ab initio approaches are suitable to unveil processes occurring at water/solid interfaces and can therefore be instrumental to delineate guidelines to improve the efficiency of these processes. In this thesis we study several systems of current interest using ab initio methods based on density functional theory (DFT). By going often beyond the use of standard DFT methods and approximations we have provided insights into processes occurring at water/solid interfaces under ambient conditions and in non stoichiometric conditions. Specifically, we will investigate the interactions between water and ZnO, an important metal-oxide especially used in industry to produce methanol. One of the most mportant results of this study is that proton hopping is dramatically enhanced under wet conditions compared to ideal ultra-high vacuum conditions. Also, we will compute the friction between liquid water in contact with 2-D layered materials, and delineate the guidelines on how to alter the friction coe cient in membranes used for desalination or osmotic power harvesting. Finally, in collaboration with Geoff Thornton's group we have investigated the role of defects on the surface chemistry of the rutile TiO2(110), which is the model oxide surface used in photocatalysis applications. On the whole, in this work we have used ab initio methods to reduce the gap between the ultra-high vacuum-style studies of adsorption on perfect defect-free surfaces and the complex behaviour of liquid/solid interfaces under technologically relevant conditions
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