304 research outputs found

    Clinical experience with power-injectable PICCs in intensive care patients

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    Introduction: In the ICU, peripherally inserted central catheters (PICCs) may be an alternative option to standard central venous catheters, particularly in patients with coagulation disorders or at high risk for infection. Some limits of PICCs (such as low flow rates) may be overcome with the use of power-injectable catheters.Methods: We retrospectively reviewed all of the power-injectable PICCs inserted in adult and pediatric patients in the ICU during a 12-month period, focusing on the rate of complications at insertion and during maintenance.Results: We collected 89 power-injectable PICCs (in adults and in children), both multiple and single lumen. All insertions were successful. There were no major complications at insertion and no episodes of catheter-related bloodstream infection. Non-infective complications during management were not clinically significant. There was one episode of symptomatic thrombosis during the stay in the ICU and one episode after transfer of a patient to a non-intensive ward.Conclusion: Power-injectable PICCs have many advantages in the ICU: they can be used as multipurpose central lines for any type of infusion including high-flow infusion, for hemodynamic monitoring, and for high-pressure injection of contrast media during radiological procedures. Their insertion is successful in 100% of cases and is not associated with significant risks, even in patients with coagulation disorders. Their maintenance is associated with an extremely low rate of infective and non-infective complications. © 2012 Pittiruti et al.; licensee BioMed Central Ltd

    A Method to Facilitate Uncertainty Analysis in LCAs of Buildings

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    Life cycle assessment (LCA) is increasingly becoming a common technique to assess the embodied energy and carbon of buildings and their components over their life cycle. However, the vast majority of existing LCAs result in very definite, deterministic values which carry a false sense of certainty and can mislead decisions and judgments. This article tackles the lack of uncertainty analysis in LCAs of buildings by addressing the main causes for not undertaking this important activity. The research uses primary data for embodied energy collected from European manufacturers as a starting point. Such robust datasets are used as inputs for the stochastic modelling of uncertainty through Monte Carlo algorithms. Several groups of random samplings between 10 1 and 10 7 are tested under two scenarios: data are normally distributed (empirically verified) and data are uniformly distributed. Results show that the hypothesis on the data no longer influences the results after a high enough number of random samplings (10 4). This finding holds true both in terms of mean values and standard deviations and is also independent of the size of the life cycle inventory (LCI): it occurs in both large and small datasets. Findings from this research facilitate uncertainty analysis in LCA. By reducing significantly the amount of data necessary to infer information about uncertainty, a more widespread inclusion of uncertainty analysis in LCA can be encouraged in assessments from practitioners and academics alike

    Thermal Performance through Heat Retention in Integrated Collector-Storage Solar Water Heaters: A Review

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    Solar thermal systems are a long-standing technology that is receiving increased attention, in terms of research and development, due to ambitious climate change targets and the need for renewable energy solutions. Integrated collector-storage solar water heaters (ICSSWHs) are a potential contributing solution and numerous studies have focussed on the optimisation of their thermal performance and efficiency. A major drawback of these systems is the heavy heat losses experienced during non-collection periods. To combat this, various heat retention strategies have been proposed and evaluated, including baffles plates, additional insulation, multiple glazing layers, selective coatings, and phase change materials. This paper aims to bring together these studies through a systematic review of the existing literature surrounding the performance of ICSSWH systems, focusing on heat retention. This review provides a comprehensive and up-to-date point of reference on relevant research and developments for researchers in this field

    Differential modulation of microglia superoxide anion and thromboxane B(2 )generation by the marine manzamines

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    BACKGROUND: Thromboxane B(2 )(TXB(2)) and superoxide anion (O(2)(-)) are neuroinflammatory mediators that appear to be involved in the pathogenesis of several neurodegenerative diseases. Because activated-microglia are the main source of TXB(2 )and O(2)(- )in these disorders, modulation of their synthesis has been hypothesized as a potential therapeutic approach for neuroinflammatory disorders. Marine natural products have become a source of novel agents that modulate eicosanoids and O(2)(- )generation from activated murine and human leukocytes. With the exception of manzamine C, all other manzamines tested are characterized by a complex pentacyclic diamine linked to C-1 of the β-carboline moiety. These marine-derived alkaloids have been reported to possess a diverse range of bioactivities including anticancer, immunostimulatory, insecticidal, antibacterial, antimalarial and antituberculosis activities. The purpose of this investigation was to conduct a structure-activity relationship study with manzamines (MZ) A, B, C, D, E and F on agonist-stimulated release of TXB(2 )and O(2)(- )from E. coli LPS-activated rat neonatal microglia in vitro. RESULTS: The manzamines differentially attenuated PMA (phorbol 12-myristate 13-acetate)-stimulated TXB(2 )generation in the following order of decreasing potency: MZA (IC(50 )<0.016 μM) >MZD (IC(50 )= 0.23 μM) >MZB (IC(50 )= 1.6 μM) >MZC (IC(50 )= 2.98 μM) >MZE and F (IC(50 )>10 μM). In contrast, there was less effect on OPZ (opsonized zymosan)-stimulated TXB(2 )generation: MZB (IC(50 )= 1.44 μM) >MZA (IC(50 )= 3.16 μM) >MZC (IC(50 )= 3.34 μM) >MZD, MZE and MZF (IC(50 )>10 μM). Similarly, PMA-stimulated O(2)(- )generation was affected differentially as follows: MZD (apparent IC(50)<0.1 μM) >MZA (IC(50 )= 0.1 μM) >MZB (IC(50 )= 3.16 μM) >MZC (IC(50 )= 3.43 μM) >MZE and MZF (IC(50 )>10 μM). In contrast, OPZ-stimulated O(2)(- )generation was minimally affected: MZB (IC(50 )= 4.17 μM) >MZC (IC(50 )= 9.3 μM) >MZA, MZD, MZE and MZF (IC(50 )> 10 μM). From the structure-activity relationship perspective, contributing factors to the observed differential bioactivity on TXB(2 )and O(2)(- )generation are the solubility or ionic forms of MZA and D as well as changes such as saturation or oxidation of the β carboline or 8-membered amine ring. In contrast, the fused 13-membered macrocyclic and isoquinoline ring system, and any substitutions in these rings would not appear to be factors contributing to bioactivity. CONCLUSION: To our knowledge, this is the first experimental study that demonstrates that MZA, at in vitro concentrations that are non toxic to E. coli LPS-activated rat neonatal microglia, potently modulates PMA-stimulated TXB(2 )and O(2)(- )generation. MZA may thus be a lead candidate for the development of novel therapeutic agents for the modulation of TXB(2 )and O(2)(- )release in neuroinflammatory diseases. Marine natural products provide a novel and rich source of chemical diversity that can contribute to the design and development of new and potentially useful anti-inflammatory agents to treat neurodegenerative diseases

    Whole-life design and resource reuse of a solar water heater in the UK

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    Passive solar systems are often designed primarily with efficiency in mind, and research efforts are concentrated towards gaining an increase in performance. However, due to the multiple materials used, their manufacturing processes, a lifespan that is usually shorter than that of buildings that these systems are applied to and the waste generated when they have reached the end of their useful life, a more holistic approach to the design and performance of these systems should be adopted. This paper reports on the environmental impact of a unique integrated collector–storage solar water heater design, experimentally tested under Scottish weather conditions, considering circular economy and reuse potential. As such, the material flows and components used are mapped against the life-cycle stages of existing European standards while ensuring an optimal efficiency. End-of-life considerations and design for disassembly and reuse are assessed and discussed. Energy payback times of 4·5 and 4·6 years can be realised for a circular and a linear approach, respectively. Operational carbon dioxide savings, which far outstrip the embodied carbon dioxide, demonstrate carbon dioxide payback times of just 7 months, when replacing an electric system. The results show that a holistic design, which promotes circular economy principles, does not compromise efficiency and economic viabilit

    The Deformation of Expanded Clay Syntactic Foams during Compression Characterized by Acoustic Emission

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    The deformation and failure mechanisms in syntactic foams with different metal matrices were investigated in this study. The syntactic foams were produced by the infiltration method using lightweight expanded clay particles (LECA) as a space holder and commercially pure Al or eutectic Al-12%Si alloy for the matrices. The samples were compressed at room temperature; simultaneously, the acoustic emission (AE) response and the surface deformation were monitored and collated with the deformation curves. In the case of the Al foam, ductile behavior with long plateau stress was observed. During this plateau regime, multiple active shear bands were detected. In contrast, the AlSi12 foam exhibited more brittle deformation behavior. At the end of the quasi-linear stage, the localization of the strain started within one large shear band, accompanied by a significant stress drop. The AE analysis revealed that the deformation was mostly governed by the fracture of LECA particles and the plastic deformation of the matrix material for both types of foams. After strain localization, in the case of the AlSi12 foam, the fracture of the matrix became significant, causing the deterioration of the sample. As for the Al foam, besides the fracture of the LECA particles, the plastic deformation of the matrix played an important role in preventing the foam from falling apart

    Application of a Clinical Workflow May Lead to Increased Diagnostic Precision in Hereditary Spastic Paraplegias and Cerebellar Ataxias: A Single Center Experience

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    The molecular characterization of Hereditary Spastic Paraplegias (HSP) and inherited cerebellar ataxias (CA) is challenged by their clinical and molecular heterogeneity. The recent application of Next Generation Sequencing (NGS) technologies is increasing the diagnostic rate, which can be influenced by patients\u2019 selection. To assess if a clinical diagnosis of CA/HSP received in a third-level reference center might impact the molecular diagnostic yield, we retrospectively evaluated the molecular diagnostic rate reached in our center on 192 unrelated families (90 HSP and 102 CA) (i) before NGS and (ii) with the use of NGS gene panels. Overall, 46.3% of families received a genetic diagnosis by first-tier individual gene screening: 43.3% HSP and 50% spinocerebellar ataxias (SCA). The diagnostic rate was 56.7% in AD-HSP, 55.5% in AR-HSP, and 21.2% in sporadic HSP. On the other hand, 75% AD-, 52% AR- and 33% sporadic CA were diagnosed. So far, 32 patients (24 CA and 8 HSP) were further assessed by NGS gene panels, and 34.4% were diagnosed, including 29.2% CA and 50% HSP patients. Eleven novel gene variants classified as (likely) pathogenic were identified. Our results support the role of experienced clinicians in the diagnostic assessment and the clinical research of CA and HSP even in the next generation era
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