96 research outputs found
Cements based on kaolinite waste
The cement industry involves high-energy consumption that generates high CO2 emissions into the atmosphere. Environmental concerns can be addressed by replacing parts of Portland cement clinkers with pozzolanic materials in mortars and concrete. Slag, fly ash and silica fume are materials considered for the planned replacement. Research studies on clay minerals, such as kaolinite, are being followed with special attention by the scientific community and the cement industry. It is well known that these minerals require an activation process to transform kaolinite (K) into metakaolinite (MK). MK is an amorphous material from the transformation of K with high pozzolanic activity, which is its capacity to react with the portlandite released during the hydration of Portland cement, generating compounds such as C–S–H gels and some aluminum-phase hydrates. One of the MK production methods is heat treatment controlled by kaolinite at temperatures in the range of 600–900°C. Different residues have been used (coal mining, paper sludge and waste from a drinking water treatment plant) activated at 600°C for 2h to elaborate blended cements. Due to their good behaviour as future eco-efficient additions, this research is a study by x-ray fluorescence (XRF), x-ray diffraction (XRD) and scanning electron microscopy (SEM) of their influence on the performances of blended cement mixtures (binary and ternary one), with substitutions of pozzolan ratio at 28 days of hydration. The porosity of pozzolanic cements decreases because of the formation of hydrated phases during pozzolanic reaction.the Spanish Ministry of the Economy and Competitiveness under coordinated projects BIA2015-65558C3-1-2-3R (MINECO/FEDER
Multi-technique characterization of a fine fraction of CDW and assessment of reactivity in a CDW/lime system
This study analysed the fine particle (<5 mm) waste generated during siliceous or calcareous (depending on the composition of the original aggregate) concrete waste crushing. In the
absence of industrial applications, such waste is amassed in open-air stockpiles on construction and
demolition wastes (CDW) management plant grounds. The aim pursued was to find an outlet for
that material in the cement industry. The starting waste, sourced from six Spanish management
facilities, was characterised for its chemical and mineralogical composition, physical properties and
pozzolanicity. The mineralogical phases in the CDW/lime system and their variations during the
pozzolanic reaction were likewise identified. The findings showed that the fine waste consisted
primarily in quartz, calcite, micas and feldspars, with smaller fractions of kaolinite and cement
anhydrous phases. No portland cement hydration phases were identified. All six types analysed
exhibited medium to low pozzolanicity, with the highest values recorded for the siliceous waste.
Ettringite, C–S–H gels and calcium aluminate hydrates (C4AH13, C4AcH12) were identified during the
pozzolanic reaction in CDW/lime system. Therefore, this type of waste can be reused as supplementary cementitious material with low-medium pozzolanic activityThis research was funded by Spain’s Ministry of Science, Innovation and Universities under National Project RTI2018-097074-B-C21, the EU’s ERDF, the Spanish National Research Agency (AEI), the Spanish Construction and Demolition Waste Recycling Association (RCDA), Sika (Madrid, Spain) and the Spanish Institute of Cement and its Applications (IECA
Soft nanostructures out of star-shaped triazines with flexible amide spacers: liquid crystals with a cubic to columnar transition with memory effect, gels and supramolecular chirality
This work reports the synthesis and characterization of a new family of star-shaped tricarboxamides with C3-symmetry that have flexible amide spacers linking a tris(triazolyl)triazine core with three trialkoxyphenyl groups. The presence of amide groups allows the formation of intermolecular hydrogen bonds that reinforce π-stacking and van der Waals interactions, promoting liquid crystalline behavior, and self-assembly in solvents leading to organogels. As determined by polarized optical microscopy, differential scanning calorimetry and X-ray diffraction on powder samples, all the three reported molecules present a hexagonal columnar (Colh) phase stable at room temperature. Interestingly, they show a transition to a cubic micellar mesophase (BCC) at high temperatures. A mechanism for this transition, which is consistent with the fragmentation of columns to form supramolecular spheres, was elucidated from X-ray studies on aligned samples. Moreover, on cooling from the BCC to the columnar phase a preferential orientation of columns occurs, according to which each cubic domain gives rise to four hexagonal domains. The ability of the synthesized structures to aggregate in solvent media was studied in a variety of organic solvents, and all of them were able to gel 1-octanol at low concentrations. X-ray studies of gels and xerogels were carried out and showed a molecular organization consistent with Colh order. FTIR studies were carried out to analyze the formation of hydrogen bonds and the influence of the length of the flexible spacer in the liquid crystalline state and in the organogels. Furthermore, the presence of a stereogenic center in the flexible amide spacer leads to macroscopic chirality in the liquid crystal state and the organogels in 1-octanol as demonstrated by circular dichroism spectroscopy.This work was financially supported by the Spanish projects PGC2018-093761-B-C31, PID2021-122882NB-I00, PID2021-126132NB-I00 MCIN/AEI/10.13039/501100011033/ and by “ERDF A way of making Europe”, the Gobierno de Aragón-FSE (E47_20R-research group) and the Basque Goverment (Project IT1458-22)
Influence of Ca/Si ratio on the microstructure and properties of blended cements elaborated with kaolinite based waste
ICCC 2015, Beijing, China, 13~16 October 2015; http://iccc2015.csp.escience.cn/dct/page/1To reduce the environmental impact of cement industries, cementitious materials are added to the manufacture of eco-efficient cements, focusing in industrial wastes. In this paper metakaolinite (MK) based industrial wastes have been mixed with cement in order to study the effect of the chemical composition of the raw material in both microstructural and mechanical properties of the pastes. Frattini test was also determined.
The selected metakaolin based industrial wastes were previously activated for two hours at temperatures around 600ºC to transform the inert waste into a cementing material. The industrial wastes materials used were coal mining and paper sludge. The second one was mixed with fly ash (50/50 w/w) in order to evaluate the performance of ternary blended cements. The mixtures were prepared with OPC and both 6 and 20% of activated industrial waste (coal mining and paper sludge + fly ash).
Prismatic samples (1x1x6 cm) were prepared with water/cement ratio of 0.5 and cured 28 days. After this time, mineralogical composition of the samples was determined by XRD as well as mechanical properties (compressive and flexural strength, total porosity, etc).
Besides, portlandite and ettringite, both monocarboaluminate and C4AH13 have been formed in the samples after 28 days of hydration. It can be observed that C4AH13 decreases as Ca/Si ratio decreases; with the opposite behaviour for the monocarboaluminate.
From the mechanical properties, porosity decreases from 1 to 28 days of curing as compressive strength increases.To the Ministry of Economy and Competiveness by the financial support (MAT2012-37005-C03-01-02-03).Peer Reviewe
Naturaleza de las dispensaciones durante el servicio de guardia de fin de semana de las farmacias en la ciudad de Teruel
Introducción: el trabajo que los farmacéuticos y otros profesionales sanitarios realizan durante el servicio de guardia tiene una importancia esencial, ya que asegura la accesibilidad al medicamento, ofreciendo consejo sanitario, seguimiento farmacoterapéutico y apoyo profesional a los pacientes fuera del horario habitual.
Objetivo: conocer la naturaleza de las dispensaciones en el servicio de guardia de las farmacias de la ciudad de Teruel durante el fin de semana.
Metodología: estudio observacional descriptivo transversal realizado en tres farmacias comunitarias de la ciudad de Teruel.
El primer período analizado comprende desde abril hasta junio de 2019 y el segundo en marzo de 2020, durante los cuatro fines de semana que las farmacias estudiadas estaban de guardia.
Resultados: de las 4.245 dispensaciones de los fines de semana analizadas en 2019, 1.059 (26,4 %) fueron medicamentos con prescripción realizada por servicios médicos de urgencia; 965 (21,8 %) de fármacos con prescripción crónica; 655 (15,2 %) no tenían prescripción médica de ningún tipo, pero se consideraron necesarios; 1.067 (25,8 %) no tenían prescripción médica y no se consideraron necesarios, y 499 (10,8 %) fueron dispensaciones no ortodoxas.
Conclusiones: el patrón de las dispensaciones durante las guardias de las farmacias es constante, independientemente de que el fin de semana sea ordinario, situación especial (Semana Santa) o situación de alarma (“COVID”). El servicio de urgencias farmacéutico no está siendo bien utilizado por la población, ya que el porcentaje de actuaciones farmacéuticas que tiene su origen en una urgencia médica es muy bajo
Morphological, chemical and electrical characterization of a family of commercial nanofiltration polyvinyl alcohol coated polypiperazineamide membranes
Three AFC membranes from PCI, of the thin film composite (TFC) nanofiltration type, have been characterized by using XPS, AFM, Contact angles, Zeta potential and permeation experiments. This plethora of complimentary methods portrays a deep and exhaustive description of these membranes that could be used to tune fabrication and modification of nanofiltration membranes to get better properties.
Morphological properties, including porosity, water permeability, fractal dimension, Wenzel parameter and roughness, correlate well with pore sizes. While functional characteristics as, for example wettability correlate well with the O/N ratio. Increasing O/N ratios should be interpreted as caused by increasing PVA coverages.
The charge on the membrane's surface is ordered in a different way for different pH but are quite similar anyway. The effect of charges on retention of 1:1, 1:2 and 2:1 salts (as tested with NaCl, Na2SO4 and CaCl2) increases with increasing O/N and wettability. Consequently, the trend of salt retentions can be explained in terms of the PVA coverage and the details of the amphoteric behavior of the three AFC membranes studied.This work was supported by the Spanish Ministry of through project MAT2016-76413-C2-1-R and the Regional Government of Castilla y León and the EU-FEDER (CLU2017-09, UIC082 and VA088G19)
Dopaminergic control of ADAMTS2 expression through cAMP/CREB and ERK: molecular effects of antipsychotics
A better understanding of the molecular mechanisms that participate in the development and clinical manifestations of schizophrenia can lead to improve our ability to diagnose and treat this disease. Previous data strongly associated the levels of deregulated ADAMTS2 expression in peripheral blood mononuclear cells (PBMCs) from patients at first episode of psychosis (up) as well as in clinical responders to treatment with antipsychotic drugs (down). In this current work, we performed an independent validation of such data and studied the mechanisms implicated in the control of ADAMTS2 gene expression. Using a new cohort of drug-naïve schizophrenia patients with clinical follow-up, we confirmed that the expression of ADAMTS2 was highly upregulated in PBMCs at the onset (drug-naïve patients) and downregulated, in clinical responders, after treatment with antipsychotics. Mechanistically, ADAMTS2 expression was activated by dopaminergic signalling (D1-class receptors) and downstream by cAMP/CREB and mitogen-activated protein kinase (MAPK)/ERK signalling. Incubation with antipsychotic drugs and selective PKA and MEK inhibitors abrogated D1-mediated activation of ADAMTS2 in neuronal-like cells. Thus, D1 receptors signalling towards CREB activation might participate in the onset and clinical responses to therapy in schizophrenia patients, by controlling ADAMTS2 expression and activity. The unbiased investigation of molecular mechanisms triggered by antipsychotic drugs may provide a new landscape of novel targets potentially associated with clinical efficacy.Acknowledgements: We are highly indebted to the participants and their families for their cooperation in this study. We also thank IDIVAL biobank (Inés Santiuste and Jana Arozamena) for clinical samples and data as well as the PAFIP members (Marga Corredera) for the data collection. This work was supported by: SAF2016-76046-R and SAF2013-46292-R (MINECO and FEDER) to B.C.F., PI16/00156 (isciii and FEDER) to J.P.V., LUCHAMOS POR LA VIDA project to F.R.J. and J.P.V., SAF2017-83702-R (MINECO and FEDER), Red TERCEL RD12/0019/0024 (ISCIII) and GVA-PROMETEO 2018/041 (Generalitat Valenciana) to S.M. J.P.V. is supported by the RyC research programme (RYC-2013-14097) and F.R.J. by the predoctoral research programme (BES-2014-070615), from MINECO and FEDER
Dopaminergic control of ADAMTS2 expression through cAMP/CREB and ERK: molecular effects of antipsychotics
© The Author(s) 2019.A better understanding of the molecular mechanisms that participate in the development and clinical manifestations of schizophrenia can lead to improve our ability to diagnose and treat this disease. Previous data strongly associated the levels of deregulated ADAMTS2 expression in peripheral blood mononuclear cells (PBMCs) from patients at first episode of psychosis (up) as well as in clinical responders to treatment with antipsychotic drugs (down). In this current work, we performed an independent validation of such data and studied the mechanisms implicated in the control of ADAMTS2 gene expression. Using a new cohort of drug-naïve schizophrenia patients with clinical follow-up, we confirmed that the expression of ADAMTS2 was highly upregulated in PBMCs at the onset (drug-naïve patients) and downregulated, in clinical responders, after treatment with antipsychotics. Mechanistically, ADAMTS2 expression was activated by dopaminergic signalling (D1-class receptors) and downstream by cAMP/CREB and mitogen-activated protein kinase (MAPK)/ERK signalling. Incubation with antipsychotic drugs and selective PKA and MEK inhibitors abrogated D1-mediated activation of ADAMTS2 in neuronal-like cells. Thus, D1 receptors signalling towards CREB activation might participate in the onset and clinical responses to therapy in schizophrenia patients, by controlling ADAMTS2 expression and activity. The unbiased investigation of molecular mechanisms triggered by antipsychotic drugs may provide a new landscape of novel targets potentially associated with clinical efficacy.This work was supported by: SAF2016-76046-R and SAF2013-46292-R (MINECO and FEDER) to B.C.F., PI16/00156 (isciii and FEDER) to J.P.V., LUCHAMOS POR LA VIDA project to F.R.J. and J.P.V., SAF2017-83702-R (MINECO and FEDER), Red TERCEL RD12/0019/0024 (ISCIII) and GVA-PROMETEO 2018/041 (Generalitat Valenciana) to S.M. J.P.V. is supported by the RyC research programme (RYC-2013-14097) and F.R.J. by the predoctoral research programme (BES-2014-070615), from MINECO and FEDER
Conclusiones y propuestas de manejo de las poblaciones y especies de anfibios y reptiles alóctonos en España
El criterio fundamental para considerar que
una especie es alóctona en el territorio español
se basa en la constatación de que la colonización
no ha sido natural, sino de origen antrópico.Peer Reviewe
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