87 research outputs found

    XPS characterization of (copper-based) coloured stains formed on limestone surfaces of outdoor Roman monuments

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    Limestone basements holding bronzes or other copper alloys artefacts such as sculptures, decorations and dedicatory inscriptions are frequently met both in modern and ancient monuments. In outdoor conditions, such a combination implies the corrosion products of the copper based alloy, directly exposed to rainwater, will be drained off and migrate through the porous surfaces, forming stains of different colours and intensities, finally causing the limestone structures to deteriorate

    The Canadian Bandaging Trial: Evidence-informed leg ulcer care and the effectiveness of two compression technologies

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    Background: Objective: To determine the relative effectiveness of evidence-informed practice using two high compression systems: four-layer (4LB) and short-stretch bandaging (SSB) in community care of venous leg ulcers. Design and Setting: Pragmatic, multi-centre, parallel-group, open-label, randomized controlled trial conducted in 10 centres. Cognitively intact adults (≥18 years) referred for community care (home or clinic) with a venous ulceration measuring ≥0.7cm and present for ≥1 week, with an ankle brachial pressure index (ABPI) ≥0.8, without medication-controlled Diabetes Mellitus or a previous failure to improve with either system, were eligible to participate.Methods: Consenting individuals were randomly allocated (computer-generated blocked randomization schedule) to receive either 4LB or SSB following an evidence-informed protocol. Primary endpoint: time-to- healing of the reference ulcer. Secondary outcomes: recurrence rates, health-related quality of life (HRQL), pain, and expenditures.Results: 424 individuals were randomized (4LB n = 215; SSB n = 209) and followed until their reference ulcer was healed (or maximum 30 months). An intent-to-treat analysis was conducted on all participants. Median time to ulcer healing in the 4LB group was 62 days [95% confidence interval (CI) 51 to 73], compared with 77 days (95% CI 63 to 91) in the SSB group. The unadjusted Kaplan-Meier curves revealed the difference in the distribution of cumulative healing times was not significantly different between group (log rank χ2 = 0.001, P = 0.98) nor ulcers recurrence (4LB, 10.1%; SSB, 13.3%; p = 0.345). Multivariable Cox Proportional Hazard Modeling also showed no significant between-bandage differences in healing time after controlling for significant covariates (p = 0.77). At 3-months post-baseline there were no differences in pain (no pain: 4LB, 22.7%; SSB, 26.7%; p = 0.335), or HRQL (SF-12 Mental Component Score: 4LB, 55.1; SSB, 55.8; p = 0.615; SF-12 Physical Component Score: 4LB, 39.0; SSB, 39.6; p = 0.675). The most common adverse events experienced by both groups included infection, skin breakdown and ulcer deterioration.Conclusions: The Canadian Bandaging Trial revealed that in the practice context of trained RNs using an evidence-informed protocol, the choice of bandage system (4LB and SSB) does not materially affect healing times, recurrence rates, HRQL, or pain. From a community practice perspective, this is positive news for patient-centred care allowing individual/family and practitioner choice in selecting compression technologies based on circumstances and context.Trial registration: clinicaltrials.gov Identifier: NCT00202267

    Molecular Tools for Monitoring the Ecological Sustainability of a Stone Bio-Consolidation Treatment at the Royal Chapel, Granada

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    Background: Biomineralization processes have recently been applied in situ to protect and consolidate decayed ornamental stone of the Royal Chapel in Granada (Spain). While this promising method has demonstrated its efficacy regarding strengthening of the stone, little is known about its ecological sustainability.Methodology/Principal Findings: Here, we report molecular monitoring of the stone-autochthonous microbiota before and at 5, 12 and 30 months after the bio-consolidation treatment (medium/long-term monitoring), employing the well-known molecular strategy of DGGE analyses. Before the bio-consolidation treatment, the bacterial diversity showed the exclusive dominance of Actinobacteria (100%), which decreased in the community (44.2%) after 5 months, and Gamma-proteobacteria (30.24%) and Chloroflexi (25.56%) appeared. After 12 months, Gamma-proteobacteria vanished from the community and Cyanobacteria (22.1%) appeared and remained dominant after thirty months, when the microbiota consisted of Actinobacteria (42.2%) and Cyanobacteria (57.8%) only. Fungal diversity showed that the Ascomycota phylum was dominant before treatment (100%), while, after five months, Basidiomycota (6.38%) appeared on the stone, and vanished again after twelve months. Thirty months after the treatment, the fungal population started to stabilize and Ascomycota dominated on the stone (83.33%) once again. Members of green algae (Chlorophyta, Viridiplantae) appeared on the stone at 5, 12 and 30 months after the treatment and accounted for 4.25%, 84.77% and 16.77%, respectively.Conclusions: The results clearly show that, although a temporary shift in the bacterial and fungal diversity was observed during the first five months, most probably promoted by the application of the bio-consolidation treatment, the microbiota tends to regain its initial stability in a few months. Thus, the treatment does not seem to have any negative side effects on the stone-autochthonous microbiota over that time. The molecular strategy employed here is suggested as an efficient monitoring tool to assess the impact on the stone-autochthonous microbiota of the application of biomineralization processes as a restoration/conservation procedure.This work was supported by the European Regional Development Fund (ERDF), Junta de Andalucía (Spain) and the “Fortalecimiento de la I+D+i” program from the University of Granada, co-financed by grant RNM-3493 and Research Group BIO-103 from Junta de Andalucía, as well as by the Spanish Government through “José Castillejo” program from the “Ministerio de Educación, Cultura y Deporte” (I+D+i 2008-2011), and by the Austrian Science Fund (FWF) under Grant “Elise-Richter V194-B20”

    Anti‑algal activity of the 12‑5‑12 gemini surfactant results from its impact on the photosynthetic apparatus

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    A rapid amplification of algal population has a negative impact on the environment and the global economy. Thus, control of algal proliferation is an important issue and effective procedures which reduce algal blooms and control algal fouling are highly desired. Gemini surfactants are considered to have a low environmental impact, therefore they seem to be a promising group of detergents which could reduce algal blooms in water systems. Furthermore, due to their emulsifying properties they could replace algaecides added to antifouling paints and decrease algae adhesion to various surfaces. In this study the toxic effect of the 12-5-12 gemini surfactant was investigated on Chlorella cells and close attention was paid to a potential mechanism of its action. At the high cell density (10.05 × 107 cells/mL) a dose-dependent cell death was found and the IC50 value was reached at the concentration of 19.6 µmol/L after 72-h exposure to the surfactant. The decrease in chlorophyll autofluorescence shows that the photosynthetic apparatus seems to be the target of the tested compound. The presented studies indicate that gemini surfactants could effectively reduce algal blooms in water systems, and if added to paints, they could decrease algal growth on external building walls or other water immersed surfaces
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