Durability aspects of electrochemical realkalisation treatment

Electrochemical realkalisation (ER) is a technique used for the repair of concrete suffering carbonation-induced corrosion of steel reinforcement. It aims at restoring high levels of pH through the application of a temporary cathodic current to steel, and subsequent production of alkalinity at the steel surface; a further mechanism of realkalisation relies on the ingress of an alkaline solution in the concrete through the surface in contact with the anode. ER does not require the replacement of carbonated concrete, if it is not damaged, and so it can be advantageous compared to conventional repair, that usually requires the removal of large amounts of mechanically sound concrete. Although ER was introduced in the 1980s and has been used since then for the repair of carbonated structures, there are still some aspects connected with its application that need further investigation. This paper presents the results of an experimental research aimed at investigating the durability of ER, considering both the realkalisation of carbonated mortar and the protection of reinforcement from corrosion

Steel reinforcement corrosion in alkali-activated fly ash mortars

Corrosion of steel rebars in concrete presents one of the main deterioration mechanisms limiting service life of the reinforced structures. The corrosion is accompanied by an expansion of the corrosion products causing high pressures, concrete cracking and finally spalling of a cover layer. Critical chloride concentration, loss of alkalinity and modeling of the steel corrosion are in researchers\u27 spotlight for decades, however reinforcement corrosion in alkali activated materials is insufficiently described and understood yet. In this work, the steel reinforcement corrosion in alkali-activated fly ash mortars is investigated in terms of electrochemical behaviour of the reinforced mortars exposed to aggressive environments such as leaching, carbonation and chloride ingress. A selected geopolymer mixture based on hard coal fly ash activated with sodium hydroxide and sodium silicate solutions is used for the steel reinforcement-corrosion experiments. The formation of passive layer on the steel rebars is observed after approx. two weeks of hardening at laboratory temperature. However, alternative heat-treatment at 80°C for several hours leads to immediate formation of the passive layer as well as to a faster strength gain (80 MPa after 24h at 80°C). Chloride-induced corrosion, leaching and carbonation resistance of the alkali activated fly ash-based concrete is studied, where leaching in deionized water or carbonation under natural conditions (~0.04 % CO2) for 300 days did not lead to corrosion of the embedded steel. On the other hand, accelerated carbonation under 100 % CO2 atmosphere lead to depassivation within two weeks. Please click Additional Files below to see the full abstract

Development of frequency-agile high-repetition-rate CO{sub 2} DIAL systems for long range chemical remote sensing

Issues related to the development of direct detection, long-range CO{sub 2} DIAL systems for chemical detection and identification are presented and discussed including: data handling and display techniques for large, multi-{lambda} data sets, turbulence effects, slant path propagation, and speckle averaging. Data examples from various field campaigns and CO{sub 2} lidar platforms are used to illustrate the issues

ISRCTN12125882 - Influence of topical anti-VEGF (Ranibizumab) on the outcome of filtration surgery for glaucoma - Study Protocol

<p>Abstract</p> <p>Background</p> <p>Excessive wound healing, with scarring of the episcleral tissue or encapsulation of the filtering bleb is the main reason for failure in trabeculectomy. Ranibizumab, an inhibitor of the Vascular Endothelial Growth Factor (VEGF), is seen as a promising candidate to prevent or treat extensive wound healing. We describe the design of a two phased study, i) assessing the local tolerability and safety of topical ranibizumab and ii) assessing the efficacy of topical ranibizumab against placebo in patients who underwent trabeculectomy with mitomycin C combined with phacoemulsification and intra ocular lens (IOL) implantation.</p> <p>Methods/Design</p> <p>In the first phase five patients that had trabeculectomy with mitomycin C combined with phacoemulsification and IOL implantation will be treated with topical ranibizumab (Lucentis^®) eye drops (2 mg/ml) four times daily for one month. The treatment will be started at the first postoperative day. Patients will be assessed for local and systemic side effects using a standardised schedule. In the second phase, after successful completion of phase 1, consenting eligible patients who underwent trabeculectomy with mitomycin C combined with phacoemulsification and IOL implantation will be randomised to either receive topical ranibizumab eye drops (2 mg/ml) four times daily for 1 month or placebo (BSS 4x/d for 1 month). Patients will be reviewed weekly for 4 weeks until conjunctival sutures are removed. Further follow up examinations are planned after 3 and six months. Assessment of differences in the intraocular eye pressure will be considered primary, and bleb appearance/vascularisation using a standardized photography and the Moorfields bleb grading system, postoperative intraocular pressure and conjunctival wound healing problems will be considered secondary outcome parameters.</p> <p>Discussion</p> <p>Anti-VEGF-antibodies might be more effective in preventing scaring and might have fewer toxic side effects than the currently used anti-metabolites and may replace them in the long term.</p> <p>Trial Registration</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN12125882">ISRCTN12125882</a></p

Control of Cell Migration and Inflammatory Mediators Production by CORM-2 in Osteoarthritic Synoviocytes

BackgroundOsteoarthritis (OA) is the most widespread degenerative joint disease. Inflamed synovial cells contribute to the release of inflammatory and catabolic mediators during OA leading to destruction of articular tissues. We have shown previously that CO-releasing molecules exert anti-inflammatory effects in animal models and OA chondrocytes. We have studied the ability of CORM-2 to modify the migration of human OA synoviocytes and the production of chemokines and other mediators sustaining inflammatory and catabolic processes in the OA joint.Methodology/Principal FindingsOA synoviocytes were stimulated with interleukin(IL)-1β in the absence or presence of CORM-2. Migration assay was performed using transwell chambers. Gene expression was analyzed by quantitative PCR and protein expression by Western Blot and ELISA. CORM-2 reduced the proliferation and migration of OA synoviocytes, the expression of IL-8, CCL2, CCL20, matrix metalloproteinase(MMP)-1 and MMP-3, and the production of oxidative stress. We found that CORM-2 reduced the phosphorylation of extracellular signal-regulated kinase1/2, c-Jun N-terminal kinase1/2 and to a lesser extent p38. Our results also showed that CORM-2 significantly decreased the activation of nuclear factor-κB and activator protein-1 regulating the transcription of chemokines and MMPs in OA synoviocytes.Conclusion/SignificanceA number of synoviocyte functions relevant in OA synovitis and articular degradation can be down-regulated by CORM-2. These results support the interest of this class of agents for the development of novel therapeutic strategies in inflammatory and degenerative conditions

Maternal consumption of canola oil suppressed mammary gland tumorigenesis in C3(1) TAg mice offspring

<p>Abstract</p> <p>Background</p> <p>Maternal consumption of a diet high in omega 6 polyunsaturated fats (n-6 PUFA) has been shown to increase risk whereas a diet high in omega 3 polyunsaturated fats (n-3 PUFA) from fish oil has been shown to decrease risk for mammary gland cancer in female offspring of rats. The aim of this study was to determine whether increasing n-3 PUFA and reducing n-6 PUFA by using canola oil instead of corn oil in the maternal diet might reduce the risk for breast cancer in female offspring.</p> <p>Methods</p> <p>Female SV 129 mice were divided into two groups and placed on diets containing either 10% w/w corn oil (which is 50% n-6 PUFA, control diet) or 10% w/w canola oil (which is 20% n-6 PUFA, 10% n-3 PUFA, test diet). After two weeks on the diets the females were bred with homozygous C3(1) TAg transgenic mice. Mother mice consumed the assigned diet throughout gestation and nursing of the offspring. After weaning, all female offspring were maintained on the control diet.</p> <p>Results</p> <p>Compared to offspring of mothers fed the corn oil diet (CO/CO group), offspring of mothers fed the canola oil diet (CA/CO group) had significantly fewer mammary glands with tumors throughout the experiment. At 130 days of age, the CA/CO group had significantly fewer tumors per mouse (multiplicity); the tumor incidence (fraction of mice with any tumor) and the total tumor weight (per mouse that developed tumor) was less than one half that of the CO/CO group. At 170 days of age, the total tumor weight per mouse was significantly less in the CA/CO group and if a tumor developed the rate of tumor growth rate was half that of CO/CO group. These results indicate that maternal consumption of canola oil was associated with delayed appearance of mammary gland tumors and slowed growth of the tumors that developed.</p> <p>Conclusions</p> <p>Substituting canola oil for corn oil is an easy dietary change for people to make; such a change to the maternal diet may decrease risk for breast cancer in the daughter.</p

Evaluation of the cancer chemopreventive efficacy of rice bran in genetic mouse models of breast, prostate and intestinal carcinogenesis

Brown rice is a staple dietary constituent in Asia, whereas rice consumed in the Western world is generally white, obtained from brown rice by removal of the bran. We tested the hypothesis that rice bran interferes with development of tumours in TAg, TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) or ApcMin mice, genetic models of mammary, prostate and intestinal carcinogenesis, respectively. Mice received rice bran (30%) in AIN-93G diet throughout their post-weaning lifespan. In TAg and TRAMP mice, rice bran did not affect carcinoma development. In TRAMP or wild-type C57Bl6/J mice, dietary rice bran increased kidney weight by 18 and 20%, respectively. Consumption of rice bran reduced numbers of intestinal adenomas in ApcMin mice by 51% (P<0.01), compared to mice on control diet. In parallel, dietary rice bran decreased intestinal haemorrhage in these mice, as reflected by increased haematocrit. At 10% in the diet, rice bran did not significantly retard ApcMin adenoma development. Likewise, low-fibre rice bran (30% in the diet) did not affect intestinal carcinogenesis, suggesting that the fibrous constituents of the bran mediate chemopreventive efficacy. The results suggest that rice bran might be beneficially evaluated as a putative chemopreventive intervention in humans with intestinal polyps

Interleukin and Growth Factor Levels in Subretinal Fluid in Rhegmatogenous Retinal Detachment: A Case-Control Study

BACKGROUND: Rhegmatogenous retinal detachment (RRD) is a major cause of visual loss in developed countries. Proliferative vitreoretinopathy (PVR), an eye-sight threatening complication of RRD surgery, resembles a wound-healing process with inflammation, scar tissue formation, and membrane contraction. This study was performed to determine the possible involvement of a wide range of cytokines in the future development of PVR, and to identify predictors of PVR and visual outcome. METHODOLOGY: A multiplex immunoassay was used for the simultaneous detection of 29 different cytokines in subretinal fluid samples from patients with primary RRD. Of 306 samples that were collected and stored in our BioBank between 2001 and 2008, 21 samples from patients who developed postoperative PVR were compared with 54 age-, sex-, and storage-time-matched RRD control patients who had an uncomplicated postoperative course during the overall follow-up period. FINDINGS: Levels of IL-1α, IL-2, IL-3, IL-6, VEGF, and ICAM-1 were significantly higher (P<0.05) in patients who developed postoperative PVR after reattachment surgery than in patients with an uncomplicated postoperative course, whereas levels of IL-1β, IL-4, IL-5, IL-7, IL-9, IL-10, IL-11, IL-12p70, IL-13, IL-15, IL-17, IL-18, IL-21, IL-22, IL-23, IL-25, IL-33, TNF-α, IFN-γ, IGF-1, bFGF, HGF, and NGF were not (P>0.05). Multivariate logistic regression analysis revealed that IL-3 (P = 0.001), IL-6 (P = 0.047), ICAM-1 (P = 0.010), and preoperative visual acuity (P = 0.026) were independent predictors of postoperative PVR. Linear regression analysis showed that ICAM-1 (P = 0.005) and preoperative logMAR visual acuity (P = 0.001) were predictive of final visual outcome after primary RRD repair. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that after RRD onset an exaggerated response of certain cytokines may predispose to PVR. Sampling at a time close to the onset of primary RRD may thus provide clues as to which biological events may initiate the development of PVR and, most importantly, may provide a means for therapeutic control

Epigenetic Regulation of a Murine Retrotransposon by a Dual Histone Modification Mark

Large fractions of eukaryotic genomes contain repetitive sequences of which the vast majority is derived from transposable elements (TEs). In order to inactivate those potentially harmful elements, host organisms silence TEs via methylation of transposon DNA and packaging into chromatin associated with repressive histone marks. The contribution of individual histone modifications in this process is not completely resolved. Therefore, we aimed to define the role of reversible histone acetylation, a modification commonly associated with transcriptional activity, in transcriptional regulation of murine TEs. We surveyed histone acetylation patterns and expression levels of ten different murine TEs in mouse fibroblasts with altered histone acetylation levels, which was achieved via chemical HDAC inhibition with trichostatin A (TSA), or genetic inactivation of the major deacetylase HDAC1. We found that one LTR retrotransposon family encompassing virus-like 30S elements (VL30) showed significant histone H3 hyperacetylation and strong transcriptional activation in response to TSA treatment. Analysis of VL30 transcripts revealed that increased VL30 transcription is due to enhanced expression of a limited number of genomic elements, with one locus being particularly responsive to HDAC inhibition. Importantly, transcriptional induction of VL30 was entirely dependent on the activation of MAP kinase pathways, resulting in serine 10 phosphorylation at histone H3. Stimulation of MAP kinase cascades together with HDAC inhibition led to simultaneous phosphorylation and acetylation (phosphoacetylation) of histone H3 at the VL30 regulatory region. The presence of the phosphoacetylation mark at VL30 LTRs was linked with full transcriptional activation of the mobile element. Our data indicate that the activity of different TEs is controlled by distinct chromatin modifications. We show that activation of a specific mobile element is linked to a dual epigenetic mark and propose a model whereby phosphoacetylation of histone H3 is crucial for full transcriptional activation of VL30 elements