123 research outputs found

    Effects of serum proteins on corrosion behavior of ISO 5832–9 alloy modified by titania coatings

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    Stainless steel ISO 5832–9 type is often used to perform implants which operate in protein-containing physiological environments. The interaction between proteins and surface of the implant may affect its corrosive properties. The aim of this work was to study the effect of selected serum proteins (albumin and γ-globulins) on the corrosion of ISO 5832–9 alloy (trade name M30NW) which surface was modified by titania coatings. These coatings were obtained by sol– gel method and heated at temperatures of 400 and 800 °C. To evaluate the effect of the proteins, the corrosion tests were performed with and without the addition of proteins with concentration of 1 g L−1 to the physiological saline solution (0.9 % NaCl, pH 7.4) at 37 °C. The tests were carried out within 7 days. The following electrochemical methods were used: open circuit potential, linear polarization resistance, and electrochemical impedance spectroscopy. In addition, surface analysis by optical microscopy and X-ray photoelectron spectroscopy (XPS) method was done at the end of weekly corrosion tests. The results of corrosion tests showed that M30NW alloy both uncoated and modified with titania coatings exhibits a very good corrosion resistance during weekly exposition to corrosion medium. The best corrosion resistance in 0.9 % NaCl solution is shown by alloy samples modified by titania coating annealed at 400 °C. The serumproteins have no significant effect onto corrosion of investigated biomedical steel. The XPS results confirmed the presence of proteins on the alloy surface after 7 days of immersion in proteincontaining solutions.The investigations were supported by the National Science Centre project No. N N507 501339. The authors gratefully acknowledge Dr. Janusz Sobczak and Dr. hab. Wojciech Lisowski from Institute of Physical Chemistry of PAS for XPS surface analyses

    Virological outcomes of second-line protease inhibitor-based treatment for human immunodeficiency virus type 1 in a high-prevalence rural South African setting: a competing-risks prospective cohort analysis

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    Background. Second-line antiretroviral therapy (ART) based on ritonavir-boosted protease inhibitors (bPIs) represents the only available option after first-line failure for the majority of individuals living with human immunodeficiency virus (HIV) worldwide. Maximizing their effectiveness is imperative. Methods. This cohort study was nested within the French National Agency for AIDS and Viral Hepatitis Research (ANRS) 12249 Treatment as Prevention (TasP) cluster-randomized trial in rural KwaZulu-Natal, South Africa. We prospectively investigated risk factors for virological failure (VF) of bPI-based ART in the combined study arms. VF was defined by a plasma viral load >1000 copies/mL ≥6 months after initiating bPI-based ART. Cumulative incidence of VF was estimated and competing risk regression was used to derive the subdistribution hazard ratio (SHR) of the associations between VF and patient clinical and demographic factors, taking into account death and loss to follow-up. Results. One hundred one participants contributed 178.7 person-years of follow-up. Sixty-five percent were female; the median age was 37.4 years. Second-line ART regimens were based on ritonavir-boosted lopinavir, combined with zidovudine or tenofovir plus lamivudine or emtricitabine. The incidence of VF on second-line ART was 12.9 per 100 person-years (n = 23), and prevalence of VF at censoring was 17.8%. Thirteen of these 23 (56.5%) virologic failures resuppressed after a median of 8.0 months (interquartile range, 2.8-16.8 months) in this setting where viral load monitoring was available. Tuberculosis treatment was associated with VF (SHR, 11.50 [95% confidence interval, 3.92-33.74]; P < .001). Conclusions. Second-line VF was frequent in this setting. Resuppression occurred in more than half of failures, highlighting the value of viral load monitoring of second-line ART. Tuberculosis was associated with VF; therefore, novel approaches to optimize the effectiveness of PI-based ART in high-tuberculosis-burden settings are needed

    Measuring effectiveness, efficiency and equity in a Payments for Ecosystem Services trial.

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    There is currently a considerable effort to evaluate the performance of payments for ecosystem services (PES) as an environmental management tool. The research presented here contributes to this work by using an experimental design to evaluate PES as a tool for supporting biodiversity conservation in the context of an African protected area. The trial employed a 'before and after' and 'with and without' design. We present the results of social and ecological surveys to investigate the impacts of the PES in terms of its effectiveness, efficiency and equity. We find the PES to be effective at bringing about additional conservation outcomes. However, we also found that increased monitoring is similarly effective in the short term, at lower cost. The major difference - and arguably the significant contribution of the PES - was that it changed the motives for protecting the park and improved local perceptions both of the park and its authority. We discuss the implications of these results for conservation efficiency, arguing that efficiency should not be defined in terms of short-term cost-effectiveness, but also in terms of the sustainability of behavioral motives. This insight helps us to resolve the apparent trade-off between goals of equity and efficiency in PES

    Experimental and computational examination of anastellin (FnIII1c)-polymer interactions

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    Using a combination of experimental and computational approaches, the interaction between anastellin, a recombinant fragment of fibronectin, and representative biomaterial surfaces has been examined. Anastellin and superfibronectin have been seen to exhibit antiangiogenic properties and other properties that may make it suitable for consideration for incorporation into biomaterials. The molecular interaction was directly quantified by atomic force microscope (AFM)-based force spectroscopy, complemented by adsorption measurements using quartz crystal microbalance (QCM). Using AFM, it was found that the anastellin molecule facilitates a stronger adhesion on polyurethane films (72.0 pN nm?1) than on poly (methyl methacrylate) films (68.6 pN nm?1). However, this is not consistent with the QCM adsorption measurements, which show no significant difference. Molecular dynamics simulations of the behavior of anastellin on polyurethane in aqueous solution were performed to rationalize the experimental data, and show that anastellin is capable of rapid adsorption to PU while its secondary structure is stable upon adsorption in water

    Evidence-based Kernels: Fundamental Units of Behavioral Influence

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    This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior

    Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

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    Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.

    Symptomatic Events in a Community Palliative Care Population: A Prospective Pilot Study.

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    Background: The palliative care population is prescribed a large number of drugs, increasing as patients deteriorate. The cumulative effects of these medications combined with underlying symptom burden can result in significant morbidity. There is an urgent need to describe possible symptomatic events that could be exacerbated by commonly prescribed drugs in palliative care and their impact. Objectives: To trial the feasibility and acceptability of determining baseline symptomatic event rates for community palliative care patients from which a composite measure of symptomatic events can be developed. Design: This prospective pilot study of patient-reported symptomatic events recruited a convenience cohort of 27 community palliative care patients in a metropolitan specialist palliative care service in Australia. Results: This study has demonstrated a high prevalence rate of symptomatic events (total crude event/participant day rate 0.87) in the study population. Conclusion: Data collection of patient-centered symptomatic events was acceptable and feasible to participants. This pilot supports a fully powered study

    Implementation of a pilot telehealth programme in community palliative care: A qualitative study of clinicians' perspectives

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    © The Author(s) 2015. Background: Telehealth technologies are an emerging resource opening up the possibility of greater support if they have utility for patients, carers and clinicians. They may also help to meet health systems' imperatives for improved service delivery within current budgets. Clinicians' experiences and attitudes play a key role in the implementation of any innovation in service delivery. Aim: To explore clinicians' perspectives on and experiences of the utilisation of a pilot telehealth model and its integration into a specialist community palliative care programme. Design: Focus groups and interviews generated data that were analysed through the lens of a realistic evaluation theoretical framework. Setting/participants: The study was conducted in a metropolitan specialist palliative care service in South Australia. Participants (n = 10) were clinicians involved in the delivery of community specialist palliative care and the piloting of a telehealth programme. Results: Service providers consider telehealth resources as a means to augment current service provision in a complementary way rather than as a replacement for face-to-face assessments. Introducing this technology, however, challenged the team to critically explore aspects of current service provision. The introduction of technologies also has the potential to alter the dynamic of relationships between patients and families and community palliative care clinicians. Conclusion: Implementation of a pilot telehealth programme in a specialist palliative community team needs to involve clinical staff in service redesign from the outset. Reliable IT infrastructure and technical support is critical for telehealth models to be effective and will aid uptake

    Identifying and explaining trend reversals of groundwater nitrate concentrations in Wallonia (Belgium)

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    Various efforts to reverse the increasing concentration of nitrates and pesticides in our groundwaters such as the Programme de Gestion Durable de l’Azote (PGDA) have been implemented in Wallonia (Belgium), driven by the EU Nitrates Directive (91/676/CEE), the Water Framework Directive (2000/60/EC) and the Groundwater Directive (2006/118/EC). The effects of these efforts on groundwater quality are complex to assess because of the non-linearity and the spatial heterogeneity of the hydrological fluxes, the numerous potential pollution sources, and the temporal delays due to the infiltration time in the vadose zone. The objective of our research is to define the environmental and anthropogenic factors affecting the effectiveness of the regulations and management practices. We use the monitoring data of 52 groundwater wells and galleries to assess the evolution of nitrate and pesticide concentration in four different water bodies. We use as indicators the contamination levels before and after the introduction of regulations and good management practices, as well as the actual trend. We then seek to predict these indicators and explain their variability by looking into characteristics which could support or undermine the regulations and good practices such as water depth, soil type, crop area or urban development. Our results should contribute to a better understanding and prediction of the groundwater quality trends at the catchment scale in Wallonia, providing guidance to catchment management
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