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Workability and strength performance of blended cements with different replacement levels have been investigated for two calcined clay mineral additions (1:1 and 2:1 type) and mixtures with limestone. The effect of fly ash addition and different water-to-cementitious ratios was also evaluated. The results show that the SO 3 content of the blended cements, and the ratio of calcined clay to limestone, can be optimized for maximum strength depending on the content of early soluble and total reactive alumina in the calcined clay. Workability is strongly affected by the calcined clay content, particularly for the 1:1 clay which greatly reduces the efficiency of superplasticizer (SP) required for achieving acceptable flow even at higher w/c ratios. On the other hand, delayed addition of the SP and/or the addition of fly ash significantly improve rheology of any binder containing calcined clay and maximize strength for same workability at a given clinker content in the paste.

Calcined clays emerge as a promising source of supplementary cementitious material, which can provide a significant lowering of the Portland clinker content in blended cements. This study focusses on sulfate resistance of calcined clay (CC) – limestone (L) – Portland cements for mortars exposed to a 0.11 M Na2SO4 solution at 5 and 20 °C after a hydration period of 91 days. The pozzolanicity, compressive strength, pore structure, and sulfate resistance of mortars containing laboratory-made metakaolin or calcined montmorillonite and limestone have been investigated in cements with 35 wt% replacement of a white Portland or an ordinary Portland clinker. The results show that all mortars with CC/(CC + L) ≥ 0.5 exhibit excellent sulfate resistance. The consumption of portlandite by the pozzolanic reactions of the calcined clays and the dilution of the Portland clinker lead to a lower amount of calcium available for the secondary formation of gypsum and ettringite, which is identified as the main reason for the excellent sulfate resistance of the ternary blends. The results suggest that calcined clay – limestone – Portland cements are included in standards as a new type of sulfate-resisting Portland pozzolana cement and Portland composite cement.

The carbonation of Portland cement, metakaolin and limestone mortars has been investigated after hydration for 91 days and exposure to 1% (v/v) CO2 at 20 °C/57% RH for 280 days. The carbonation depths have been measured by phenolphthalein whereas mercury intrusion porosimetry (MIP), TGA and thermodynamic modeling have been used to study pore structure, CO2 binding capacity and phase assemblages. The Portland cement has the highest resistance to carbonation due to its highest CO2 binding capacity. The limestone blend has higher CO2 binding capacity than the metakaolin blends, whereas the better carbonation resistance of the metakaolin blends is related to their finer pore structure and lower total porosity, since the finer pores favor capillary condensation. MIP shows a coarsening of the pore threshold upon carbonation for all mortars. Overall, the CO2 binding capacity, porosity and capillary condensation are found to be the decisive parameters governing the carbonation rate.

The present work focuses on key parameters which determine the best strength performance of two calcined clay mineral additions (1:1 and 2:1 type) and mixtures with limestone. Additionally, alternative options rather than increased admixture dosage have been investigated to mitigate the rheological problems typically found when calcined clays are incorporated to cement.

The reduction of the clinker content in concrete by replacing cement with supplementary cementitious materials (SCM) is widely used to lower the environmental impact of concrete. However, for some SCMs such as calcined clay this often leads to higher water requirements for the same concrete consistence. This severely limits the widespread implementation of green concrete technologies, both in practical terms, and in meeting the requirements of relevant concrete standards such as the national annexes to EN 206. In order to overcome this, a shift in mind-set from prescriptive to performance-based design criteria would be beneficial. Thus, we have proposed a performance-based design approach for the selection of binder systems, which we have successfully applied it to several combinations of SCMs. In this paper the procedure is described for a binder system consisting of calcined clay, limestone filler and fly ash. A parametric study was carried out on mortars, which included rheological properties, compressive strength and chloride migration. The requirements for each parameter was chosen based on the intended concrete application (highway bridge) and values obtained for a reference mix typically used for the application, i.e. a concrete that fulfils current Danish regulations. The proposed alternative binder system features a CO2 footprint reduction of 30% compared to the reference concrete mix. However, the alternative concrete mix does not conform with current Danish regulation on the minimum w/c ratio.

The relation between the chemical composition of calcium-silicate-hydrate (C-S-H) phases and its influence on the compressive strength of cementitious materials is investigated by a new approach where prisms of C-S-H phases have been synthesized directly by the reaction of calcium hydroxide, amorphous SiO2 and water. The synthesized samples employ molar Ca/Si ratios of 0.83, 1.0, 1.25 and 1.50, and the compressive strengths and age-depending changes of the pastes have been followed for up to three months of hydration, after which the microstructures were characterized. The model pastes feature most characteristics of hydrated cements, including zones of different density but similar chemical composition. The experimental data demonstrates that the compressive strengths of the C-S-H pastes increase for decreasing Ca/Si ratio for all synthesized samples and testing ages. The molar volumes of the C-S-H phases decrease with decreasing Ca/Si ratio, which along with the related higher surface areas may partly explain the differences in strength development.

The potential of calcium aluminosilicate (CAS) glasses as supplementary cementitious materials is studied in terms of the development of compressive strength for mortars containing a mixture of Portland cement, CAS glass and limestone. In addition, the impact of internal and external alkali-activation of the cementitious systems on the mortar performances is investigated. Internal alkali-activation is obtained by adding alkali oxides to the CAS glass system, whereas external alkali-activation is realized by hydration of the blended cements containing alkali-free CAS glasses using alkaline solutions. For the internally alkali-activated systems and the alkali-free mortars, higher strengths are achieved in comparison to the reference mortar prepared from plain ordinary Portland cement. In contrast, the externally alkali-activated mortars exhibit lower compressive strengths, implying the importance of both the immediate availability of alkali ions in the cementitious system and the increased dissolution rate of the glass particles caused by the network depolymerization. The glasses are also studied by thermal analysis and the results are used to calculate the theoretical CO2 emissions. The lowest embodied CO2 emission is estimated for the blends containing alkali-activated CAS glasses. This article is protected by copyright. All rights reserved.

Thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and thermodynamic modelling have been used to obtain Friedel's salt profiles for saturated mortar cylinders exposed to a 2.8 M NaCl solution. Comparison of the measured Friedel's salt profiles with the total chloride profiles indicates that only a minor part of the chloride ions is bound in Friedel's in the studied Portland cement (P) and limestone blended (L) cement. The chloride binding capacity with respect to the formation of Friedel's salt by consumption of monocarbonate is reached for the P and L mortars, where only a fraction of about 20% of the amount of C3A is found to contribute to formation of Friedel's salt. Higher amounts of Friedel's salt are formed in the metakaolin containing mortars. However, the limited chloride ingress depths prevent quantification of the potential full chloride binding capacity of Friedel's salt in these mortars. The measured amounts of Friedel's salt by TGA and the portlandite profiles show that the maximum amount of Friedel's salt is found in the region with limited leaching of calcium, which is in good agreement with the predicted Friedel's salt profiles. © 2017. This is the authors’ accepted and refereed manuscript to the article. Locked until 5.1.2019 due to copyright restrictions. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

Resistance to chloride ingress of ten different binders was investigated. Most of the binders were prepared with 35% substitution of a new clinker by limestone filler, calcined clay, burnt shale and/or siliceous fly ash. Mortar samples with similar design compressive strength after 90 days were exposed to artificial sea-water for 270 days. The results indicate that the use of alternative binders may lead to up to around 15% reduction in CO2 emission without compromising 90 days compressive strength and resistance to chloride ingress in marine exposure. This is the accepted version of the article.

This paper reports an initial screening of potential new binders for concrete with reduced CO2- emission. Mortars cured saturated for 90 days are compared with regard to a) compressive strength of mortars with similar water-to-binder ratio, and b) chloride ingress in similar design strength mortars exposed to seawater. The reference used was a binder composition typical for a Danish ready mixed concrete for aggressive environments and strength class C35/45. Based on the present investigation and assumptions up to around 15% reduction in CO2 emission from binder production might be obtained without compromising the 90 days compressive strength and resistance to chloride ingress in marine exposure by using selected alternative binders. This is the authors' accepted manuscript of the article.

Human single-chain Fv directed against fibroblast growth factor receptor 3 (FGFR3) have been shown to block proliferation of RT112 bladder carcinoma cells in vitro. Here, we examined the ability of the recombinant gelonin toxin (rGel) to enhance this inhibitory effect in vitro and in vivo on the bladder cancer cell line RT112 and the corresponding xenografts. Immunotoxins were genetically engineered by fusing FGFR3-specific Fv fragments (3C) to the NH2 terminus of rGel and expressed as a soluble protein in Escherichia coli. The 3C/rGel fusion construct showed an IC50 of 200 nmol/L against log-phase RT112 cells compared with 1,500 nmol/L for free rGel. Immunofluorescence studies showed that the 3C/rGel construct internalized rapidly into the cytoplasm of RT112 cells within 1 h of exposure. The mechanism of immunotoxin-induced cell death was found to be mediated by apoptosis. RT112 tumor xenografts in severe combined immunodeficient mice treated with 50 mg/kg 3C/rGel exhibited considerable growth delay relative to control tumors and a significant reduction of 55% to 70% in mean tumor size. Immunohistochemical analysis showed that tumors from mice treated with 3C/rGel displayed considerable apoptotic damage compared with control groups. Subcellular location of FGFR3 in immunotoxin-treated tumors indicated a translocation of FGFR3 to the nuclear membrane in contrast to tumors from saline-treated controls. These results show that FGFR3-driven immunotoxins may be an effective therapeutic agent against human bladder and other tumor types overexpressing FGFR3. [Mol Cancer Ther 2008;7(4):862–73]

The use of calcined clays as SCM’s provides a valuable contribution to the reduction in CO2 emission associated with cement production since they can be produced at significantly lower temperatures and do not involve a calcination reaction. Moreover, it is well known that binary blends of Portland cement and small amounts of limestone powder can increase the strength of the resulting concrete. In this study we have investigated the substitution of cement by metakaolin and limestone as well as blends of cement, metakaolin, silica fume and limestone, in all cases with a 35 wt% replacement level of Portland cement. The phase assemblages of the hydrated blends are characterized by XRD, 27Al and 29Si MAS NMR spectroscopy, and thermodynamic modelling. The X-ray diffractograms show that larger amounts of the AFm phases are formed for the samples containing both limestone and calcined clay whereas 29Si MAS NMR studies of the hydrated pastes provide information about the uptake of Al in the C–S–H phase and structural details about the resulting C–A–S–H phases. 27Al MAS NMR is used to follow the formation of the hydrated aluminate species, in particular the formation of stratlingite. The results from XRD and NMR after prolonged hydration are compared with the phase assemblages predicted from thermodynamic modelling. Overall, good agreements are observed between the experiments and the modeled predictions.

Membrane-anchored ephrinB2 and its receptor EphB4 are involved in the formation of blood and lymphatic vessels in normal and pathologic conditions. Eph/ephrin activation requires cell-cell interactions and leads to bidirectional signaling pathways in both ligand- and receptor-expressing cells. To investigate the functional consequences of blocking ephrinB2 activity, 2 highly specific human single-chain Fv (scFv) Ab fragments against ephrinB2 were generated and characterized. Both Ab fragments suppressed endothelial cell migration and tube formation in vitro in response to VEGF and provoked abnormal cell motility and actin cytoskeleton alterations in isolated endothelial cells. As only one of them (B11) competed for binding of ephrinB2 to EphB4, these data suggest an EphB-receptor–independent blocking mechanism. Anti-ephrinB2 therapy reduced VEGF-induced neovascularization in a mouse Matrigel plug assay. Moreover, systemic administration of ephrinB2-blocking Abs caused a drastic reduction in the number of blood and lymphatic vessels in xenografted mice and a concomitant reduction in tumor growth. Our results show for the first time that specific Ab-based ephrinB2 targeting may represent an effective therapeutic strategy to be used as an alternative or in combination with existing antiangiogenic drugs for treating patients with cancer and other angiogenesis-related diseases.

Melanoma is the most aggressive skin cancer once metastasis begins; therefore, it is important to characterize the molecular players involved in melanoma dissemination. The chemokine receptor CXCR4 and the membrane-bound metalloproteinase MT1-MMP are expressed on melanoma cells and represent candidate molecules for the control of metastasis. Using human melanoma transfectants that either overexpress or silence CXCR4 or MT1-MMP, or that have a combination of overexpression and interference of these proteins, we show that CXCR4 and MT1-MMP coordinate their activities at different steps along melanoma cell metastasis into the lungs. Results from in vivo xenograft mouse models of melanoma lung colonization and mice survival and short-term, homing nested polymerase chain reaction experiments from lung samples indicated that CXCR4 is required at early phases of melanoma cell arrival in the lungs. In contrast, MT1-MMP is not needed for these initial steps but promotes subsequent invasion and dissemination of the tumor with CXCR4. Investigation of potential cross talk between CXCR4 and MT1-MMP revealed that MT1-MMP accumulates intracellularly after melanoma cell stimulation with the CXCR4 ligand CXCL12, and that this process involves the activation of the Rac-Erk1/2 pathway. Subsequent to cell contact with specific basement membrane proteins, MT1-MMP redistributes to the cell membrane in a phosphatidylinositol 3-kinase-dependent manner. These results suggest that combination therapies that target CXCR4 and MT1-MMP should improve the limitations of the current therapies for metastatic melanoma. Copyright © American Society for Investigative Pathology.