Nuestros investigadores

Gene therapy with an adeno-associated vector (AAV) serotype 8 encoding the human ATPase copper-transporting beta polypeptide (ATP7B) complementary DNA (cDNA; AAV8¿ATP7B) is able to provide long-term copper metabolism correction in 6-week-old male Wilson disease (WD) mice. However, the size of the genome (5.2 kilobases [kb]) surpasses the optimal packaging capacity of the vector, which resulted in low-yield production; in addition, further analyses in WD female mice and in animals with a more advanced disease revealed reduced therapeutic efficacy, as compared to younger males. To improve efficacy of the treatment, an optimized shorter AAV vector was generated, in which four out of six metal¿binding domains (MBDs) were deleted from the ATP7B coding sequence, giving rise to the miniATP7B protein (delta57-486-ATP7B). In contrast to AAV8-ATP7B, AAV8-miniATP7B could be produced at high titers and was able to restore copper homeostasis in 6- and 12-week-old male and female WD mice. In addition, a recently developed synthetic AAV vector, AAVAnc80, carrying the miniATP7B gene was similarly effective at preventing liver damage, restoring copper homeostasis, and improving survival 1 year after treatment. Transduction of approximately 20% of hepatocytes was sufficient to normalize copper homeostasis, suggesting that corrected hepatocytes are acting as a sink to eliminate excess of copper.

A new range of grouts prepared by air lime and metakaolin (MK) as a pozzolanic admixture has been obtained by using as dispersing agents two polymers, namely poly-naphthalene sulfonate (PNS) and lignosulfonate (LS), with the aim of improving the fluidity of the fresh grouts. Fluidity and setting times of the grouts were assessed. Differences in the molecular architecture and in the anionic charge density explained the different adsorption of the polymers and the different performance. The higher anionic charge of PNS and its linear shape explained its better adsorption and effectiveness. The pozzolanic reaction was favoured in grouts with PNS, achieving the highest values of compressive strength (4.8 MPa after 182 curing days). The addition of PNS on lime grouts slightly decreased the frost resistance of the grouts (from 24 freeze-thaw cycles for the polymer-free samples to 19 or 20 cycles with 0.5 or 1 wt % of PNS). After the magnesium sulphate attack, grouts were altered by decalcification of hydrated phases and by formation of hexahydrite and gypsum. A protective role of portlandite against magnesium sulphate attack was clearly identified. Accordingly, the polymer LS, which preserves a significant amount of Ca(OH)2, could be an alternative for the obtaining of grouts requiring high sulphate attack resistance.

Mortars with two different binders (Portland cement (PC) and high alumina cement (HAC)) were modified upon the bulk incorporation of nano-structured photocatalytic additives (bare TiO2, and TiO2 doped with either iron (Fe-TiO2) or vanadium (V-TiO2)). Plastic and hardened state properties of these mortars were assessed in order to study the influence of these nano-additives. Water demand was increased, slightly by bare TiO2 and Fe-TiO2, and strongly by V-TiO2, in agreement with the reduction of the particle size and the tendency to agglomerate. Isothermal calorimetry showed that hydration of the cementitious matrices was accelerated due to additional nucleation sites offered by the nano-additives. TiO2 and doped TiO2 did not show pozzolanic reactivity in the binding systems. Changes in the pore size distribution, mainly the filler effect of the nano-additives, accounted for the increase in compressive strengths measured for HAC mortars. A complex microstructure was seen in calcium aluminate cement mortars, strongly dependent on the curing conditions. Fe-TiO2 was found to be homogeneously distributed whereas the tendency of V-TiO2 to agglomerate was evidenced by elemental distribution maps. Water absorption capacity was not affected by the nano-additive incorporation in HAC mortars, which is a favourable feature for the application of these mortars.

Our data demonstrate that AAV8-AAT-ATP7B-mediated gene therapy provides long-term correction of copper metabolism in a clinically relevant animal model of WD providing support for future translational studies.

Polynaphtalenesulfonate (PNS) and lignosulfonate (LS) were tested as superplasticizers in pastes and mortars of pure air lime and air lime with a pozzolanic additive, nanosilica (NS). LS showed a better plasticizing effect than PNS: the flowability of the samples with LS as well as the slump retention over time was larger. LS strongly hindered carbonation due to its ability to form Ca2+ complexes. In mortars with NS, PNS was seen to interfere with the C-S-H formation, resulting in lower mechanical strengths. Adsorption isotherms and zeta potential showed that PNS was more adsorbed than LS onto lime and C-S-H particles. PNS acted mainly through electrostatic repulsion owing to its high anionic charge density and flat adsorption. However, LS was more efficient as superplasticizer in air lime media, steric hindrance being the main mechanism responsible for avoiding flocculation. Furthermore, LS yielded high compressive strengths in mortars with NS.

Oxaliplatin (L-OH), a platinum derivative with good tolerability is currently combined with Cetuximab (CTX), a monoclonal antibody (mAb), for the treatment of certain (wild-type KRAS) metastatic colorectal cancer (CRC) expressing epidermal growth factor receptor (EGFR). Improvement of L-OH pharmacokinetics (PK) can be provided by its encapsulation into liposomes, allowing a more selective accumulation and delivery to the tumor. Here, we aim to associate both agents in a novel liposomal targeted therapy by linking CTX to the drug-loaded liposomes. These EGFR-targeted liposomes potentially combine the therapeutic activity and selectivity of CTX with tumor-cell delivery of L-OH in a single therapeutic approach. L-OH liposomes carrying whole CTX or CTX-Fab¿ fragments on their surface were designed and characterized. Their functionality was tested in vitro using four human CRC cell lines, expressing different levels of EGFR to investigate the role of CTX-EGFR interactions in the cellular binding and uptake of the nanocarriers and encapsulated drug. Next, those formulations were evaluated in vivo in a colorectal cancer xenograft model with regard to tumor drug accumulation, toxicity and therapeutic activity. In EGFR-overexpressing cell lines, intracellular drug delivery by targeted liposomes increased with receptor density reaching up to 3-fold higher levels than with non-targeted liposomes. Receptor specific uptake was demonstrated by competition with free CTX, which reduced...

Aflatoxins (AFs) content was analyzed in bovine feedstuff from dairy farms in Spain.¿None of the samples exceeds AFB1 legislation but a high incidence (90%) was found.¿Geographical location, unlike season or feeding system, had limited influence on AFs.¿Organic homemade feedstuff showed non-detected level of AFs throughout the study. Aflatoxins (B1, B2, G1 and G2) are produced by the fungi Aspergillus (A. flavus and A. parasiticus) in substrates used in cattle feed manufacturing. Aflatoxin M1 (AFM1) is a major metabolite of Aflatoxin B1 (AFB1) which may be present in milk from animals that consume contaminated feed. Levels of aflatoxins in 78 dairy cow feedstuff samples from 40 farms located in Navarra were determined by HPLC-FLD (High Performance Liquid Chromatography with fluorescence detection) and post-column derivatization. The influence of geographical location, season and type of feeding system on aflatoxin content was studied. The climatic profile of AFB1 pointed to spring as the season with the highest aflatoxin level (0.086¿g/kg), followed by winter and summer (0.075 and 0.030¿g/kg, respectively), and to a lesser degree, autumn (0.017¿g/kg). Moreover, wet and dry TMR (Total Mixed Ration) feeding systems (i.e. AFB1: 0.076 and 0.068¿g/kg; Aflatoxin G1 (AFG1): 0.050 and 0.011¿g/kg, respectively) showed a greater content of the analyzed aflatoxins in comparison with compound feed (i.e. AFB1: 0.039¿g/kg; AFG1: 0.007¿g/kg). The fact that the majority of the samples collected were based on compound feed shows that this type was preferred by most dairy farmers. The undetectable levels of aflatoxins in the organic homemade compound feedstuff are also worth mentioning. While none of the feedstuff samples contained amounts over those permitted under European legislation (5¿g/kg), the theoretical extrapolation of the carryover rate suggested in previously published experiments of AFB1 to AFM1 in secreted cow's milk predicts that only one of the feed samples studied had a positive aflatoxin level (53.4ng/kg) higher than the legal limit for raw cow's milk.

The performance of air lime mortars modified by the incorporation of large amounts of nanostructured colloidal silica ¿ nanosilica, NS - (6, 10 and 20 wt.% with respect to lime) was the main objective of this work. Fresh mixture properties (water demand, setting time and plastic shrinkage), mechanical strengths up to one year and specimens¿ durability after accelerated ageing conditions (climatic chamber, freeze-thaw cycles and sulfate attack by MgSO4 corrosion test) were evaluated. NS was seen to have a strong pozzolanic activity in air lime media. Although the addition of NS gave rise to an increase in volume contraction, the superficial cracking caused by the drying shrinkage was reduced. A noticeable increase in the compressive strength values was observed in the NS-bearing mortars owing to the NS filler effect and the C-S-H formation, as proved by SEM examination and MIP analysis. A honeycomb-shaped network of C-S-H phases appeared as the prevailing microstructure in mortars with large NS additions. In the face of accelerated ageing processes, the presence of NS made the mortars more durable, delaying the progress of decay.

The oxidative stability of seven oils with different fatty acid profiles was assessed. Oxidation at 0, 2 and 4 h at 180 °C was monitored by measuring the absorbance of thiobarbituric acid reactive substances (TBARS) along the absorption spectrum (300¿600 nm), the volatile aldehydes (HS-SPME¿GC¿MS) and the fatty acid profile (FID-GC). TBARS absorption spectrum behavior depended on the lipid composition of heated oils. Higher absorbance increments during heating were noticed at 390 nm compared to 532 nm (from 2 to 21 fold higher depending on the oil), pointing to its better sensitivity to detect oxidation. Furthermore, a close relationship between ABS390, the loss of polyunsaturated fatty acids and their corresponding oxidation compounds (volatile aldehydes) was revealed by Principal Component Analysis. Multiparametric equations allowed predicting the formation of volatile aldehydes of heated oils by measuring only two parameters: TBARS390 during their heating, and the lipid profile in unheated oils (MUFA, ¿-3 and ¿-6). Results pointed out the interest of choosing ABS390 when the oxidative evolution of vegetable oils under heating is assessed by the TBARS test

Two polycarboxylate ether copolymers were assessed as superplasticizers (SPs) for hydrated lime pastes modified with two reactive compounds, nanosilica (NS) and ceramic metakaolin (MK). Characterization of the molecular structure of the SPs by Size Exclusion Chromatography, XRD, FTIR and MALDI-TOF (Matrix Assisted Laser Desorption Ionization Time-of-Flight) mass spectrometry was performed. The structures of the polymers were seen to be star- and worm-like shapes. A close relationship was found between the molecular architecture and the flowability of the pastes, being the star-shaped plasticizer the most efficient. Zeta potential assessment allowed us to elucidate a steric hindrance as the main action mechanism for these polymers. The large specific surface area of nanosilica led to a large SPs consumption as compared with metakaolin with lower surface area. However, SPs in MK¿lime samples were attached favourably on the C¿S¿H and aluminate hydrates, so that the dispersing action was greater with respect to NS¿lime suspensions.

Topical therapy is the ideal outpatient treatment of cutaneous leishmaniasis (CL) because of the ease of administration and lower cost. It could be suitable as monotherapy for localized cutaneous leishmaniasis (LCL) or in combination with systemic therapies for more severe forms of the disease. Although paromomycin (PM) ointment can be recommended for the treatment of LCL caused by Leishmaniamajor, a more effective topical treatment should be achieved regarding the physicochemical properties of this aminoglucoside and its rather poor intrinsic antileishmanial activity, that hampers the accumulation of enough amount of drug in the dermis (where the infected macrophages home) to exert its activity. In this work, we determined a 50% effective dose of 5.6 ¿M for a novel compound, bis-4-aminophenyldiselenide, against L. major intracellular amastigotes. This compound and PM were formulated in chitosan hydrogels and ex vivo permeation and retention studies in the different skin layers were performed with pig ear skin in Franz diffusion cells. The results showed that less than 2¿4% of the diselenide drug penetrated and permeated through the skin. In contrast, the percentage of PM penetration was about 25¿60% without important retention in the skin. When topically applied to lesions of L. major infected BALB/c mice, the novel diselenide chitosan formulation was unable to slow lesion progression and reduce parasite burden. Considerations during the process of novel drug development and

Polyphosphate-modified calcium aluminate cement matrices were prepared by using aqueous solutions polluted with toxic metals as mixing water to obtain waste-containing solid blocks with improved management and disposal. Synthetically contaminated waters containing either Pb or Cu or Zn were incorporated into phosphoaluminate cement mortars and the effects of the metal¿s presence on setting time and mechanical performance were assessed. Sorption and leaching tests were also executed and both retention and release patterns were investigated. For all three metals, high uptake capacities as well as percentages of retention larger than 99.9% were measured. Both Pb and Cu were seen to be largely compatible with this cementitious matrix, rendering the obtained blocks suitable for landfilling or for building purposes. However, Zn spoilt the compressive strength values because of its reaction with hydrogen phosphate anions, hindering the development of the binding matrix.

BACKGROUND: A combined technological approach was applied in the development of healthier dry fermented sausages: a partial substitution of the pork back fat by pre-emulsified linseed oil and a partial replacement of sodium chloride with calcium ascorbate at two different levels, leading to low amounts of salt (14gSalt and 10gSalt, with 14 g and 10 g NaCl per kg of mixture, respectively). RESULTS: The developed products (14gSalt and 10gSalt) showed adequate results for aw (0.85 and 0.87) and pH (4.98 and 5.21), and low lipid oxidation values (1.4 x 104 and 1.5 x 105 g malondialdehyde (MDA) kg1). The lipid modification led to a significantly higher supply of -3 (23.3 g kg1) compared to the control (3.2 g kg1). Simultaneously, reductions of 38% and 50% in sodium content and a calcium supply of 4 and 5.2 g kg1 were achieved in the 14gSalt and 10gSalt formulations, respectively, compared to the control products (26 g salt and 0.87 g kg1 Ca). Instrumental analysis of colour and texture and sensory studies demonstrated that the organoleptic quality of the new formulations was similar to that of traditional products. CONCLUSIONS: The developed dry fermented sausages showed healthier properties than traditional ones owing to their reduced sodium and higher calcium content and a significant supply of -3 fatty acids. (c) 2012 Society of Chemical Industry

The effect of storage temperature (65 degrees C, 48 h) on the oxidative stability of a food-grade water-in-oil-in-water (W/O/W) emulsion was studied by comparison with an oil-in-water (O/W) emulsion. The emulsions were prepared with linseed oil or olive oil, and in each case, two antioxidants were evaluated, an aqueous Melissa lyophilized extract and BHA. Emulsions were characterized using bright field light microscopy and the oxidation was monitored by measuring the lipid hydroperoxides, thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD) and trienes (CT), alpha-tocopherol and Lipophilic Oxygen Radical Absorbance Capacity (L-ORACFL) Assay. A great stability of olive oil emulsions was observed, without noticing differences between antioxidants or type of emulsion. This behavior was not observed in linseed oil emulsions. In this case the lipophilic antioxidant (BHA) seemed to be more efficient delaying the lipid oxidation in W/O/W emulsions than the water Melissa extract while the opposite occurs in the O/W emulsion. The type of antioxidant is a key factor in controlling oxidation in W/O/W and O/W emulsions which are prepared with highly polyunsaturated oils, but not in the case of highly monounsaturated ones.

Tyrosol and caffeic acid are biophenols that contribute to the beneficial properties of virgin olive oil. The influence of hydroxypropyl-beta-cyclodextrin (HP beta-CD) on their respective antioxidant capacities was analyzed. The ORAC antioxidant activity of tyrosol (expressed as mu M Trolox equivalents/mu M Tyrosol) was 0.83 +/- 0.03 and it increased up to 1.20 +/- 0.11 in the presence of 0.8 mM HP beta-CD. However, the ORAC antioxidant activity of caffeic acid experienced no change. The different effect of HP beta-CD on each compound was discussed. In addition, the effect of increasing concentrations of different cyclodextrins in the development of ORAC-fluorescence (ORAC-FL) assays was studied. The ORAC signal was higher for HP beta-CD, followed by M beta-CD, beta-CD, gamma-CD and finally alpha-CD. These results could be explained by the formation of inclusion complexes with fluorescein.

The ability of calcium aluminate cement (CAC) to encapsulate toxic metals (Pb, Zn and Cu) was assessed under two curing conditions. Changes in the consistency and in the setting time were found upon the addition of the nitrates of the target metals. Both Pb and Cu caused a delay in CAC hydration, while Zn accelerated the stiffening of the mortar. Compressive strengths of the metal-doped mortars, when initially cured at 60ºC / 100%RH, were comparable with that of the free-metal mortar. Three different pore size distribution patterns were identified and related to the compounds identified by XRD and SEM. Sorbent capacities of CAC for the toxic metals were excellent: a total uptake was achieved for up to 3 wt.% loading of the three metals. In this way, CAC mortars were perfectly able to encapsulate the toxic metals, allowing the use of CAC for waste management as proved by the leaching tests.

A pre-emulsified mixture of linseed and algae oils (15/10) and stabilized with 686 ppm of a lyophilized water extract of Melissa officinalis, was successfully applied in dry fermented sausages to increase the ¿-3 PUFA content. The objective of this work was to evaluate the stability of this modified formulation during the storage and to compare it to that of a traditional formulation. Traditional and modified products were stored during 90 days at 4 ºC in aerobic conditions. Fatty acid profiles, TBARS and volatile compounds derived from oxidation were analyzed at 0, 30 and 90 days of storage. The fatty acid profiles did not significantly change along the storage period. The stabilizing effect of the natural antioxidants of M. officinalis could contribute to detect no losses of ¿-3 PUFA in Modified (30 days: 2.13 g/100 g of product, 90 days: 2.33 g/100 g of product), whereas in Control products a slightly significant reduction was detected (30 days: 0.34 g/100 g of product, 90 days: 0.29 g/100 g of product). After 90 days, the increases of TBARS and hexanal content were much higher in Control than in Modified (Control: 1.41 mg MDA/kg & 17,915 ng dodecane/kg of dry matter; Modified: 0.48 mg MDA/kg & 2,496 ng dodecane/kg of dry matter). In conclusion, the lyophilized water extract of M. officinalis protected high ¿-3 PUFA of dry fermented sausages from oxidation along the storage time, guaranteeing the nutritional improvements achieved with the modified formulation.

In this work, the Film Method (FM), Reverse-Phase Evaporation (REV), and the Heating Method (HM) were applied to prepare PEG-coated liposomes of oxaliplatin with natural neutral and cationic lipids, respectively. The formulations developed with the three methods, showed similar physicochemical characteristics, except in the loading of oxaliplatin, which was statistically lower (P < 0.05) using the HM. The incorporation of a semi-synthetic lipid in the formulation developed by FM, provided liposomes with a particle size of 115 nm associated with the lowest polydispersity index and the highest drug loading, 35%, compared with the other two lipids, suggesting aft increase in the membrane stability. That stability was also evaluated according to the presence of cholesterol, the impact of the temperature, and the application of different cryoprotectants during the lyophilization. The results indicated long-term stability of the developed formulation, because after its intravenous in vivo administration to HT-29 tumor bearing mice was able to induce an inhibition of tumor growth statistically higher (P < 0.05) than the inhibition caused by the free drug. In conclusion, the FM was the simplest method in comparison with REV and HM to develop in vivo stable and efficient PEG-coated liposomes of oxaliplatin with a loading higher than those reported for REV. (C) 2012 Elsevier B.V. All rights reserved.

The incidence of aflatoxin M-1 (AFM(1)) in 69 different infant formulae marketed in Spain between 2007 and 2008 was studied and dietary intake estimated. Samples were analysed using an HPLC method coupled with fluorescence detection after immunoaffinity column clean-up. The toxin was detected in 26 formulae (37.7%) at levels below the permissible limit set by EC legislation, giving a range of 0.6-11.6 ng kg(-1) with a mean value of 3.1 ng kg(-1). Increasing occurrence was found in those formulae produced by the less complex manufacturing processes affecting casein/whey protein ratio: pre-term, 14.3%; starter, 35.3%; follow-up, 42.1%; toddler 87.6%; while hypoallergenic and lactose-free were totally exempt. Additionally, the influence of main protein source and physical state (powdered and ready-to-use formula) on AFM(1) occurrence was evaluated leading to similar conclusions. Dietary AFM1 weekly intake was observed to be stable around 1 ng kg(-1) bw for standard formula and 0.1 ng kg(-1) bw for pre-term feeding.

Biodegradable poly (lactic-co-glycolic) acid (PLGA) nanoparticles incorporating cisplatin have been developed to evaluate its in vivo efficacy in tumor-bearing mice. In vitro Study proved two mechanisms of action for cisplatin depending on the dose and the rate at which this dose is delivered. In vivo study, 5 mg/kg of cisplatin nanoparticles administered to mice, exhibited a tumour inhibition similar to free cisplatin, although the area under cisplatin concentration-time Curve between 0 and 21 days (AUC(0-21)) had lower Value for the formulation than for drug solution (P < 0.05). This result was associated with a higher activation of apoptosis in tumor, mediated by caspase-3, after nanoparticles administration. Toxicity measured as the change in body weight, and blood urea nitrogen (BUN) plasma levels showed that cisplatin nanoparticles treatment did not induce significant changes in both parameters compared to control, while for free drug, a statistical (P < 0.01) increase was observed. In addition, a good correlation was found between time profiles of tumor volume and vascular endothelial growth factor (VEGF) plasma levels, suggesting that its expression could help to follow the efficacy of the treatment. Therefore, the PLGA nanoparticles seem to provide a promising carrier for cisplatin administration avoiding its side effects without a reduction of the efficacy, which was consistent with a higher activation of apoptosis than free drug.

Aflatoxins (AFB1, AFB2, AFG1 and AFG2) are immunosuppressant, mutagenic, teratogenic and carcinogenic agents with a widespread presence in foodstuffs. Since human exposure to aflatoxins occurs primarily by contaminated food intake, and given the greater susceptibility of infants to their adverse effects, the quantification of these mycotoxins in infant food based on cereals is of relevance. Aflatoxin levels were determined in 91 Spanish infant cereals classified in terms of non- and organically produced and several types from 10 different manufacturers, using a extraction procedure followed by inmunoaffinity column clean-up step and HPLC with fluorescence detection (FLD) and post-column derivatisation (Kobra Cell system). Daily aflatoxin intake was also assessed. Preliminary analysis showed a valuable incidence of detected infant cereal samples at an upper concentration level than the detection limit for total aflatoxin (66%), corresponding to a 46, 40, 34 and 11% for AFB1, AFB2, AFG1 and AFG2, respectively. Lower aflatoxin values (median, Q1, Q3) in conventional infant cereal (n = 74, AFB1: LOD (n.d.; 0.02), AFB2: n.d. (n.d.; 0.01), AFG1: LOD (n.d.; 0.004), and AFG2: n.d. (n.d.; LOD) and total AF (AFtotal): 0.01 (LOD; 0.04 mu g kg-1) in comparison with infant cereal ecologically produced (n = 17, AFB1: 0.02 (0.02; 0.21), AFB2: n.d. (n.d.; 0.03), AFG1: 0.02 (0.01; 0.05), and AFG2: 0.007 (n.d.; 0.02) and AFtotal: 0.05 (0.03; 0.31 mu g kg-1) were found. In addition, five organic formulations (3.11, 1.98, 0.94, 0.47 and 0.21 mu g kg-1) exceeded European AFB1 legislation (0.10 mu g kg-1) versus two conventional cereals (0.35 and 0.12 mu g kg-1). According to the type of infant cereal, those with cocoa had the highest aflatoxin levels. Gluten-free and cereals with dehydrated fruits had an intermediate level and milk- or honey-based cereals and multi-cereals contained the lowest levels. With the exception of the non-compliant cocoa-based organic formulation, none of the infant cereals analyzed gave a higher intake of 1 ng kg-1 body weight per day, suggesting that infants fed on infant cereals are exposed to a low health hazard. Nevertheless, manufacturers are advised for continued efforts in routine monitoring and a more careful selection of raw material to minimize aflatoxin levels in these infant foods.

Different rendering mortars were prepared by mixing air lime and air lime-pozzolanic nanosilica with TiO2 and sodium oleate as, respectively, photocatalytic and water repellent agents, added in bulk. The aim of the work was to design and obtain new rendering mortars with improved durability focusing in the reduction of the water absorption of these materials and in their self-cleaning and biocide effect. To achieve a better distribution of the TiO2 particles, which was expected to enhance their efficiency, different dispersing agents were also incorporated to the fresh mixtures. Four diverse polycarboxylate ethers superplasticizers and a poly-naphthalene-sulfonate were tested. Workability and fluidity of the fresh rendering mortars were determined to guarantee the applicability of the final products. Water contact angle was monitored with the aim of assessing the hydrophobicity of the mortars lent by the water repeller. The biocide effect was studied by means of the culture of a strain of Pseudomonas fluorescens. The colonization of the mortars¿ surface was analyzed by determining the number of colonies forming units (CFU) after several days subjecting the samples to suitable T and RH conditions. At the same time, the surface of the mortars was irradiated with solar light to activate the photocatalyst. Results showed the efficiency of the sodium oleate in reducing the water uptake of the rendering mortars.

Active coatings to be applied onto hardened surfaces of lime rendering and masonry mortars and stones of the Built Heritage were developed. Nano-heterostructures of TiO2/ZnO (50:50 and 10:90) were obtained by Flame Spray Pyrolysis as photocatalytic agents with expanded sensitivity towards solar light, instead of the restricted UV dependence of the pure TiO2 or ZnO. A superhydrophobic medium was simultaneously prepared and photocatalytic nanoparticles were added to obtain the coatings. The active products were expected to prevent the water absorption of the substrates and the subsequent degradation effects as well as to allow the stones and mortars to act as self-cleaning materials, reducing the dirt deposition and the biological colonization. Dispersions were applied onto the surface of lime mortars and siliceous stone. Measurements of the photocatalytic oxidation activity of the coatings were carried out by means of the NO degradation, showing a very good efficiency of the nanoparticles even at long term tests (values of NO oxidation of ca. 35%). Water contact angle assessment evidenced a strong hydrophobization of the treated surfaces, with WCA values higher than 140º. The results proved the synergistic effect of these coatings with respect to the durability of the treated substrates, giving rise to a promising way of preventive conservation for building materials of the Cultural Heritage.

El presente trabajo tiene como principal objetivo estudiar las interacciones que se producen cuando se adicionan separadamente dos superplastificantes (PNS ¿sulfonato de polinaftaleno- y LS ¿lignosulfonato-) a un conglomerante aéreo (cal aérea Cl 90-S) y a uno hidráulico formado por cal aérea a la que se le ha añadido metacaolín como material puzolánico, y los efectos que dichas adiciones tienen en las propiedades de los sistemas. Para la fabricación de los morteros, se empleó árido calcáreo. Adicionalmente, se efectuaron ensayos de durabilidad en morteros con la composición citada, sometiéndolos a ciclos de hielo-deshielo y a ataque con sulfatos. Aunque se realizaron algunas medidas con las pastas en estado fresco, la mayoría de los experimentos (resistencia a compresión y a flexión, TG-ATD, DRX, FTIR-ATR, porosimetría de intrusión de mercurio) se realizaron tras períodos de fraguado del mortero de 7, 28, 91, 182 y 365 días. Se detectaron fases silicatadas y silicoaluminatadas en los morteros estudiados, a pesar de que las experiencias se realizaron a temperatura ambiente y con un bajo porcentaje de material puzolánico (¿20 %). La presencia de LS impidió el proceso de carbonatación, lo que a su vez provocó un decrecimiento en los valores de resistencia mecánica cuando se trataba de morteros hidráulicos. Se observó asimismo una mayor porosidad y un mayor tamaño medio de poro en el caso de sistemas con LS. La durabilidad (ciclos hielo-deshielo) de los morteros mejoró notable

A new range of repair lime mortars were obtained by using as superplasticizer a polynaphthalene sulfonate-based polymer (PNS) and metakaolin as pozzolanic addition. Adsorption isotherms showed that PNS exhibited a high affinity for air lime particles with 52.08 mg¿g-1 as maximum sorption capacity in pure air lime media. Mathematical treatment of experimental data showed an optimal adjustment to a Freundlich model, in which interactions arising from multilayer adsorption are taken into account. The experimental results suggested a great interaction of PNS with air lime media (pure air lime or air lime with MK). Zeta potential curves of air lime systems titrated with PNS showed a larger zeta potential reduction, giving rise to a charge reversal, as a consequence of the high anionic charge density of this polymer (2.44 meq of anionic charge¿g-1). A flat adsorption was proposed as the attachment model of this admixture, owing to its higher anionic charge density and to its linear shape. The electrostatic repulsion was then the main action mechanism to explain the PNS function. In the hardened state, the combination of PNS and MK resulted sometimes in moderate mechanical strength increases and in a clear enhancement of the durability in the face of freezing-thawing cycles.

The obtaining of self-cleaning mortars is very interesting to apply them in Built Heritage. Atmospheric pollutants, mainly carbonaceous particles and gases like NOx and SO2 can lead to severe aesthetic and functional damages in artworks. In the case of mortars and renders, the use of photocatalysts -usually based on TiO2- can be worthy of consideration. Photocatalysts, after being activated by light, are able to oxidize pollutants avoiding their deposition onto building materials. In this work, different air lime mortars modified upon the addition of TiO2-based photocatalysts were obtained and studied. Photocatalysts can be incorporated in bulk and the changes in fresh state properties were studied as well as the effect of the presence of the photocatalysts on the pore structure and mechanical resistance. Finally, the photocatalytic efficiency of these materials was carried out by means of a NOx abatement test. Results showed that the presence of the photocatalysts had a positive impact on the preservation of the lime mortars characteristics.

The behaviour of different superplasticizers admixtures was assessed for hydrated lime pastes and mortars. Sometimes, air lime pastes and mortars were modified with two supplementary cementing materials (SCMs), namely nanosilica (NS) and metakaolin (MK). Two different polycarboxylate ethers, a lignosulfonate and a naphthalene condensed sulfonate superplasticizer were added to lime pastes and mortars and their effects on fresh-state properties as well as on the mechanical strengths were evaluated. A close relationship was found between the molecular architecture of the plasticizers and the flowability of the pastes. Zeta potential assessment allowed us to elucidate the main action mechanisms for these admixtures. In the case of polycarboxylate ethers, the large specific surface area of nanosilica led to a large SPs consumption as compared with metakaolin with lower surface area. However, polycarboxylate ethers in MK-lime samples were attached favourably to the C-S-H and aluminate hydrates, so that the dispersing action was greater with respect to NS-lime suspensions.

Proceedings of the 5th Historic Mortars Conference (HMC 2019) held at the University of Navarra in Pamplona from the 19th to the 21st June 2019.

El Fórum Ibérico de la Cal, FICAL, es una asociación sin ánimo de lucro cuyo objetivo es el desarrollo de la investigación, la formación y la difusión de la producción y el uso de la cal. Después de las exitosas V Jornadas celebradas en el LNEC de Lisboa, la Universidad de Navarra toma el relevo y organizará en Pamplona, en la Facultad de Ciencias, las VI Jornadas FICAL, del 28 al 30 de mayo de 2018. Estas Jornadas están abiertas a participantes de distintas procedencias e intereses: restauradores, arquitectos y arquitectos técnicos, químicos, geólogos, ingenieros civiles y de materiales, historiadores, científicos, profesionales del sector industrial, estudiantes, empresas productoras¿ con el común denominador de conocer más posibilidades de aplicación, características, comportamiento y aspectos innovadores y tecnológicos en relación con la cal. Se conocen aplicaciones de la cal desde tiempos inmemoriales, particularmente en construcción: morteros, soportes decorativos y pictóricos. La cal es un material íntimamente ligado al Patrimonio Histórico-Artístico y se sigue produciendo a partir de las mismas materias primas. Destacan, entre sus características, la plasticidad de las argamasas que utilizan cal, su capacidad higroscópica y desinfectante, sus propiedades aislantes y su durabilidad. La cal es perfectamente compatible con estructuras antiguas, es idónea para procesos de restauración y rehabilitación, pero también tiene interés en obra nueva porque aporta estabilidad,