Tumores sinusales en el Cementiri Vell (Banyoles, Girona) 2008

X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200

Life Cycle Assessment of Alkali Activated Cement compared to Ordinary Portland Cement

Approximately 8% of the global emissions of CO2 are originated by the cement industry, which consumes on average between 4 to 6 GJ per ton of cement. Ordinary Portland Cement (OPC) is the most used cement for construction purposes. Every year, around 4 billion tonnes (Gt) of OPC are manufactured. For each kg of OPC produced, 0.81 kg of CO2 is generated. Therefore, seeking cements with more environmentally friendly manufacturing process, economically viable, and socially relevant is necessary. One of the most promising materials are the Alkali-Activated Cements (AAC), where its components are an aluminosilicate precursor and alkaline activators. The precursor used in this study is Weathered Bottom Ash (WBA), a waste obtained from the Municipal Solid Waste Incineration (MSWI). On the other hand, the alkaline activators are sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). The name of the AAC developed is Sustainable-AAC (Sust-AAC). This project is focused on searching for new materials that could reduce the use of OPC as a building material. To be able to assess the associated environmental impacts, a comparison between AAC and OPC (CEM I) through a Life Cycle Assessment (LCA) following the standards ISO 14040:2006 and ISO 14044:2006 is performed. The LCA methodology allows identification and quantification of relevant inputs and outputs of the system, thus, evaluating the potential environmental impacts associated. The system boundary of this project is cradle-to-gate and the functional unit of the assessment is 1 ton of commercial cement. The OPC inventory is carried out through the values obtained in GaBi Software and the Sust-AAC inventory is made from the previous studies performed in the DIOPMA research group, on a laboratory scale. The results show that the OPC has higher impact on global warming, energy consumption, water consumption, and mineral extraction categories compared to Sust-AAC. In OPC manufacturing, the kiln stage is the most energy intensive stage (by the chemical reaction and by the fossil fuel requirement) and therefore, has the most significant environmental impact in terms of CO2 emissions and energy consumption. In contrast, the highest environmental impacts on the Sust-AAC are due to the production of Na2SiO3. The main reason for the energysaving is because Sust-AAC production does not need a kiln with high temperatures. In addition, the use of waste as raw material promotes a circular economy and, at the same time, reduces the extraction of natural resources. Then, the environmental performance in the Sust-AAC is promising compared to OPC. Sust-AAC is suitable to be used as lightweight material and as insulation material for thermal insulating applications. This application can contribute to realising operational energy savings and performance benefits

Amelogénesis imperfecta tipo IE. a propósito de una familia afectada

En este artículo se revisa el concepto de Amelogénesis imperfecta a propósito de una familia afectada de Amelogénesis imperfecta tipo lE, según la clasificación de WITKOP. En primer lugar se hace un breve repaso de la entidad y de las complejas clasificaciones que sobre ella se han realizado, para pasar posteriormente a detallar la clínica, etiopatogenia y modo de transmisión del subtipo lE (IIa según la clasificación tradicional). Después se detalla el caso clínico de la familia que nos ocupa y finalmente se comentan las posibilidades terapéuticas, así como la importancia de la prevención en este tipo de pacientes

Geopolymers based on the valorization of Municipal Solid Waste Incineration residues

he proper management of Municipal Solid Waste (MSW) has become one of the main environmental commitments for developed countries due to the uncontrolled growth of waste caused by the consumption patterns of modern societies. Nowadays, municipal solid waste incineration (MSWI) is one of the most feasible solutions and it is estimated to increase in Europe where the accessibility of landfill is restricted. Bottom ash (BA) is the most significant by-product from MSWI as it accounts for 85-95 % of the solid product resulting from combustion, which is classified as a non-hazardous residue that can be revalorized as a secondary aggregate in road sub-base, bulk lightweight filler in construction. In this way, revalorization of weathered BA (WBA) for the production of geopolymers may be a good alternative to common reuse as secondary aggregate material; however, the chemical process to obtain these materials involves several challenges that could disturb the stability of the material, mainly from the environmental point of view. Accordingly, it is necessary that geopolymers are able to stabilize heavy metals contained in the WBA in order to be classified as non-hazardous materials. In this regard, the SiO2/Al2O3 ratio plays an important role for the encapsulation of heavy metals and other toxic elements. The aim of this research is to formulate geopolymers starting from the 0-2 mm particle size fraction of WBA, as a unique raw material used as aluminumsilicate precursor. Likewise, leaching tests of the geopolymers formulated were performed to assess their environmental impact. The findings show that it is possible to formulate geopolymers using 100 % WBA as precursor, although more investigations are needed to sustain that geopolymer obtained can be considered as non-hazardous materials

Cancerización de campo: revisión del concepto

El concepto de cancerización de campo sugiere que las mucosas del tracto aerodigestivo superior de un determinado paciente, sometidas de forma similar a los agentes cancerígenos habituales, tienen un mayor riesgo de desarrollar nuevos carcinomas. Desde su acuñamiento, el término se ha empleado para describir múltiples terrenos de enfermedad premaligna, con una prevalencia mayor de la esperada de aparición de múltiples tumores primarios o secundarios locales y la presencia de tumores distantes sincrónicos. Las técnicas moleculares han permitido profundizar en el conocimiento de la relación entre estas lesiones. Si bien hay diferencias metodológicas en la forma de identificar los orígenes clonales de las lesiones, algunos estudios indican que es frecuente la extensión clonal lateral de la enfermedad premaligna o maligna. Ante esta patología, se están investigando diversas alternativas preventivas y terapéuticas, como el screening poblacional, los retinoides o la terapia génica, que pueden aportar beneficios a los pacientes con lesiones premalignas y malignas en la región de cabeza y cuello

Swine as an experimental model in dentistry: a proposal of surgical approach

Swine is widely used as an experimental model in several areas of medicine based on its anatomical and physiological similarities to humans. In this report, we describe an external surgical approach on the mandible of the swine as a suitable experimental model in dentistry. Several biomaterials were implanted by using this technique in order to evaluate the degree of bone regeneration as well as the suitable sites to accomplish perforation

Estado periodontal y de la mucosa oral en un grupo de embarazadas: estudio clínico

Los cambios hormonales en el embarazo se reflejan en la salud periodontal de las pacientes, se pretende cuantificar y evaluar estos cambios en la cavidad oral de 165 pacientes embarazadas, así como el estado de su mucosa oral y relacionar su percepción de salud oral con los resultados de su estado periodontal. Métodos: Pacientes de revisión de rutina de un centro de atención primaria. Se les realiza una ex-ploración donde se evalúa el estado periodontal, mediante el Índice de Necesidad de Tratamiento Periodontal de la Comunidad (C.P.I.T.N.), y el estado de las mucosas. Los dientes escogidos para el sondaje fueron el 16, 11, 26, 36, 31 y 46 de cada paciente y se tomó como valor representativo el más alto de todos los sextantes. 56 acudieron para realizarse una reevaluación. Resultados: De las 165 embarazadas el 5% (9) fueron consideradas invalorables. El 35% dieron como resultado valor 0 (57); el 46% valor 1 (76); el 12% valor 2 (20); y el 2% valor 3 (1). De las 56 que acudieron a la reevaluación el 23% (13) mejoraron, el 10% (6) empeoraron y el 66% (37) se mantu-vieron. De las 165 sólo una presentó una lesión en mucosas, una ránula. Conclusiones: Aunque hubo un porcentaje sin patología periodontal, 35%, la mayoría padecía gin-givitis (46%) y algunas periodontitis (14%). Por tanto consideramos importante recomendar a las pacientes embarazadas una exploración bucodental y realizar una labor preventiva en todas las pacientes en edad fértil con el fin de evitar consecuencias negativas

Fluidised-bed incineration bottom ash as the sole precursor of alkali-activated binders: A comparison with bottom ash from grate incinerators

The novel formulation of alkali-activated binders (AABs) using incineration bottom ash (IBA) from fluidised bed (FB) combustion technology as a sole precursor was assessed. In addition, IBA-FB was compared with IBA from moving grate (IBA-MG) combustion technology. The AABs formulated with IBA-FB (AAB-FB) and IBA-MG (AAB-MG) were also evaluated from a physicochemical, mechanical, and environmental perspective. The results revealed that specific surface area in IBA-FB hinders the retention of kneading water of fresh pastes, affecting the workability, consistency, porosity, and mechanical strength of AAB-FB. Moreover, the low calcium content of IBA-FB requires that the formulated AABs must be cured at higher curing temperatures to ensure the formation of (N,C) ASH gels, while the high calcium content of IBA-MG promotes the formation of CSH gels at room temperature. The compressive strength results demonstrated that AAB-MG (≈ 11 MPa) and AAB-FB (≈ 8 MPa) could be used for non-structural purposes

Epsomite as flame retardant treatment for wood: preliminary study

The effect of epsomite as flame retardant for wood has been investigated and compared with a commercial boron salt. Both flame retardants have been introduced into wood samples by vacuum impregnation. Epsomite is a hydrated sulphate salt with a water solubility of 731 g¿L-1 at room temperature. Thanks to this high solubility it was possible to obtain elevated epsomite loadings in comparison with the borax salt. Flame retardancy was evaluated by means of the limiting oxygen index, the dripping test and the exposition to a direct flame (Bunsen test). The results showed that the addition of epsomite increases the limiting oxygen index, delays the time to ignition and the evolution of the temperatures trough the wood