Degradación de estructuras urbanas generada por crecimiento de plantas y actividad microbiana

The purpose of this study was to isolate microorganisms associated to surface-affected concrete structures and to measure the in vitro dissolution of concrete based on the release of elements such as calcium and silicon. Although many microorganisms were detected only a fungus was capable of significantly decreasing the culture medium pH and releasing both elements. The molecular characterization allowed to identify the microorganism as Aspergillus carbonaurius, a citric-acid producing fungus that dissolved concrete in the in vitro test. After seven days of incubation, the soluble calcium concentration in the uninoculated culture medium containing concrete was 172.3 mg/L, while in the inoculated medium it was 525.0 mg/L. The soluble silicon concentration in the uninoculated medium was 10.3 mg/L, while in the inoculated medium it was 50.1 mg/L. These findings showed that plants and microorganisms rendered a synergistic effect accelerating the biodeterioration of concrete.El objetivo de este estudio fue aislar microorganismos de la superficie de estructuras urbanas de concreto deterioradas y medir su capacidad para disolver in vitro muestras de concreto, basada en la liberación de elementos como el calcio y el silicio. De todos los microorganismos aislados sólo un hongo fue capaz de disminuir el pH y disolver el concreto. Este hongo fue identificado a nivel molecular como Aspergillus carbonaurius, un productor de ácido cítrico. Después de siete días de incubación, se encontró que la concentración de calcio soluble en el medio de cultivo no inoculado fue 172,3 mg/L, mientras que en el medio inoculado era de 525,0 mg/L. La concentración de silicio soluble en el medio no inoculado fue de 10,3 mg/L, mientras que en el medio inoculado fue de 50,1 mg/L. Estos hallazgos mostraron que las plantas y los microorganismos producen un efecto sinérgico que acelera el biodeterioro del concreto

Aprovechamiento de residuos industriales para la síntesis de clínker belítico

The synthesis of belite clinker was studied using industrial wastes: paper sludge, cement kiln dust and rice husk ashes, as substitutes for natural raw materials. Wastes were characterized by XRF, XRD and TG analysis. Different formulations were prepared to produce clinker at 1300, 1350 and 1400 °C. The clinker obtained was characterized using optical microscopy, XRD and f-CaO content determined by ethylene glycol method. Finally, the hydration of prepared cements with the clinkers was evaluated by isothermal microcalo­rimetry. It was found that by mixing paper sludge, cement kiln dust and rice husk ashes, it is possible to obtain belite clinker with f-CaO content below 0.5%, in clinkering temperatures between 1350 °C and 1400 °C without the use of natural raw materials. It was found that these cements have a high hydration kinetic, far above the rate of Ordinary Portland Cement, due mainly by the amorphous phase content in clinkers obtained.En el presente trabajo se estudió la síntesis de clínker belítico usando residuos industriales: lodo papelero, polvo de horno de cemento y ceniza de cascarilla de arroz, como sustitutos de las materias primas naturales. Los residuos se caracterizaron mediante FRX, DRX y TGA. Se prepararon formulaciones para producir clínker a 1300, 1350 y 1400 °C. El clínker se caracterizó usando microscopía óptica, DRX y f-CaO. Finalmente, se evaluó la hidratación de cementos preparados a partir de los clínkeres obtenidos. Se encontró que, con lodo papelero, polvo de horno de cemento y ceniza de cascarilla de arroz, es posible obtener clínker belítico con contenidos de f-CaO ≤ 0,5%, a temperaturas entre 1350 y 1400 °C sin el uso de materias primas de origen natural. Se encontró una alta cinética de hidratación, muy por encima de la velocidad de hidratación de un cemento Portland convencional, principal­mente debido al contenido de fase amorfa en los clínkeres obtenidos

Development of bronchiectasis during long-term rituximab treatment for rheumatoid arthritis

Here the cases of three female patients who received long-term rituximab treatment for seropositive, erosive and deforming rheumatoid arthritis was reported. After rituximab treatment, they presented with recurrent sinusitis and pneumonia, followed by the subsequent development of bronchiectasis. A temporal relationship between rituximab treatment and the onset of respiratory complications was exposed as a possible pathogenic mechanism

Neurological Disorders in Primary Sjögren's Syndrome.

International audienceSjögren's syndrome is an autoimmune disease characterized by an autoimmune exocrinopathy involving mainly salivary and lacrimal glands. The histopathological hallmark is periductal lymphocytic infiltration of the exocrine glands, resulting in loss of their secretory function. Several systemic manifestations may be found in patients with Sjögren's syndrome including neurological disorders. Neurological involvement ranges from 0 to 70% among various series and may present with central nervous system and/or peripheral nervous system involvement. This paper endeavors to review the main clinical neurological manifestations in Sjögren syndrome, the physiopathology, and their therapeutic response

GLACIERS IN COLOMBIA: RECENT EVOLUTION AND PRESENT CONDITION

Las montañas nevadas colombianas, han experimentado durante el Holoceno, importantes avances y retrocesos en su masa glaciar como respuesta fundamental a cambios climáticos. A partir de análisis con sensores remotos (fotografías aéreas e imágenes de satélite) se ha podido reconstruir la evolución de área desde el Neoglacial para los seis masas glaciares actuales del país, teniendo una extensión para el periodo 2002 - 2003 de 55 km2, lo cual representa una disminución cercana al 80% durante los últimos 150 años. Actualmente la pérdida de área se estima entre el 1 y 3% anual. En cuanto a la pérdida de espesor de hielo se ha observado en un periodo de 10 meses un promedio de tres metros aproximadamente en el volcán nevado Santa Isabel (Cordillera Central). Estos datos anuncian la inevitable desaparición del hielo en la alta montaña colombiana en tan solo algunas décadas.   Palabras clave: Glaciar, ablación, balance de masa, retroceso glaciar.        The snow-covered mountains Colombian, have experimented during the Holoceno, important advances and backward movements in their mass glacier like fundamental answer to climatic changes. From analysis with remote sensors (aerial photographies and satellite images) it has been possible to reconstruct the evolution of area from Neoglacial for the six masses present glaciers of the country, being had an extension for period 2002 - 2003 of 55 km2, which represents a diminution near 80% during last the 150 years. At the moment the lost one of area is considered between 1 and annual 3%. As far as the loss of thickness of ice to observed in a period of 10 months an average of three meters approximately in the snow-covered volcano Santa Isabel (Central mountain range). These data announce the inevitable disappearance of the ice in the high Colombian mountain in only some decades.   Key words: Glacier, ablation, balance of mass, backward movement glacier. &nbsp

Evaluación de cementos obtenidos por activación alcalina de ceniza de carbón con NaOH curados a bajas temperaturas

The temperature at which the alkaline activation process takes place is a significant factor in the evolution of the mechanical properties of coal ash cementitious base material. In this work, the influence of temperature (8 a 38 °C) and curing time (3 and 28 days) on the mechanical properties of the alkaline synthesis of two coal ashes was evaluated through the study of the mineralogical evolution of the cementitious phases by XRD and FTIR. We found that the type of zeolite, a synthesis product, depends on the study factors. For values above 28 °C and at least 7 days, alkalinely activated cements with compressive strength above 20 MPa were achieved. Other parameters, such as SiO2/Al2O3 ratio, percentage of unburned coal and particle-size distribution, should be taken into account in the variation of mechanical performance.La temperatura a la cual se desarrolla el proceso de activación alcalina es un factor significativo en la evolución de las propiedades mecánicas de material cementante base ceniza de carbón. En este trabajo se evaluó, a través del estudio de la evolución mineralógica de las fases cementantes por DRX y FTIR, la influencia de la temperatura (8 a 38 °C) y tiempo (3 y 28 días) de curado sobre las propiedades mecánicas de la síntesis alcalina de dos cenizas de carbón. Se encontró que el tipo de zeolita, producto de la síntesis, depende de los factores de estudio. Para valores superiores a 28 °C y mínimo 7 días, se lograron cementos activados alcalinamente con resistencias superiores a 20 MPa. Otros parámetros, como la relación SiO2/Al2O3, el porcentaje de carbón inquemado y la distribución del tamaño de partícula, se deben de tener en cuenta en la variación del desempeño mecánico

GLACIARES COLOMBIANOS: EVOLUCIÓN RECIENTE Y ESTADO ACTUAL

    The snow-covered mountains Colombian, have experimented during the Holoceno, important advances and backward movements in their mass glacier like fundamental answer to climatic changes. From analysis with remote sensors (aerial photographies and satellite images) it has been possible to reconstruct the evolution of area from Neoglacial for the six masses present glaciers of the country, being had an extension for period 2002 - 2003 of 55 km2, which represents a diminution near 80% during last the 150 years. At the moment the lost one of area is considered between 1 and annual 3%. As far as the loss of thickness of ice to observed in a period of 10 months an average of three meters approximately in the snow-covered volcano Santa Isabel (Central mountain range). These data announce the inevitable disappearance of the ice in the high Colombian mountain in only some decades.   Key words: Glacier, ablation, balance of mass, backward movement glacier.  Las montañas nevadas colombianas, han experimentado durante el Holoceno, importantes avances y retrocesos en su masa glaciar como respuesta fundamental a cambios climáticos. A partir de análisis con sensores remotos (fotografías aéreas e imágenes de satélite) se ha podido reconstruir la evolución de área desde el Neoglacial para los seis masas glaciares actuales del país, teniendo una extensión para el periodo 2002 - 2003 de 55 km2, lo cual representa una disminución cercana al 80% durante los últimos 150 años. Actualmente la pérdida de área se estima entre el 1 y 3% anual. En cuanto a la pérdida de espesor de hielo se ha observado en un periodo de 10 meses un promedio de tres metros aproximadamente en el volcán nevado Santa Isabel (Cordillera Central). Estos datos anuncian la inevitable desaparición del hielo en la alta montaña colombiana en tan solo algunas décadas.   Palabras clave: Glaciar, ablación, balance de masa, retroceso glaciar.   &nbsp

The atrial resting potential distribution within a fibrotic zone and its effects on the conduction on non-fibrotic zones: A simulation study

Atrial fibrillation (AF) is a heart condition commonly diagnosed within the clinical praxis. During an AF episode, rapid and irregular heartbeats are present and they underly a complex electrical activity. It is known that the atrial structural alterations play a role in establishing the fibrillatory propagation patterns. However, the specific mechanisms are not fully understood. Fibrosis is a hallmark of AF and it represents structural abnormalities that disturbs the atrial electrical conduction. In this work, the behavior of the cardiomyocytes resting action potential in a fibrotic tissue, under distinct textures, is studied. A computational model of atrial electrophysiology is implemented. For the fibrosis model, spatial complex-order derivatives are used. Several values for the derivative order are tested in order to generate different degrees of structural complexity. The fibrosis model also includes cellular heterogeneity through the presence of fibroblasts coupled to cardiomyocytes. Diffuse, interstitial and compact fibrosis textures are implemented in a 2D domain and the amount of fibrosis is varied. The distribution of the resting potential is assessed using the Shannon entropy and the tissue is stimulated in order to evaluate the conduction velocity. The results indicate that, the distinct fibrosis structural conditions generate a wide range of resting potential distributions: from normal to heavy-tailed. The entropy values indicate the changes in the resting potential distribution when the structural complexity varies. Such analysis evinced that the amount of fibrosis generates specific entropy curves respect the derivative order. Moreover, the conduction velocity outside the fibrotic area is affected by the fibrotic configuration, which evinces the long-range effect of the fractional derivative operator and agrees with experimental observations. These results suggest that the proposed complex-order model can be useful for modeling fibrosis during atrial fibrillation and the entropy approach allows characterizing the wide range of fibrillatory scenarios under distinct fibrosis configurations.info:eu-repo/semantics/publishedVersio

Analgesic effect and side effects of celecoxib and meloxicam in canine hip osteoarthritis

Objective. To evaluate the pharmacological, clinical and toxicological effects of celecoxib and meloxicam for analgesia for 30 days in dogs with hip osteoarthritis. Materials and methods. Twenty-four patients were evaluated, 75% were females with an average age of 7.16 ± 2.06 years and twenty five percent were males with an average age of 7.83 ± 2.22 years. All patients had hip osteoarthritis and they were randomized into two groups; one group received oral celecoxib 5 mg/kg every 12 hours during one month and the second group received oral meloxicam 0.2 mg/kg every 24 hours during 1 month. The patients were evaluated for analgesia, and hematological, renal, liver, and coagulation tests on days 0, 10th and 30th after treatment initiation, and a gastric endoscopy on day 30. Statistical analysis was performed using a HSD Tukey test and c2 with a 5% level of statistical significance. Results. Both drugs reduced articular pain according to the Melbourne scale during the 30 days of treatment (p≤0.05). Hematological, renal, hepatic and coagulation tests were normal in both treatment groups. All patients presented chronic gastritis on endoscopy on day 30th. Conclusions. Both drugs decreased pain at day 30th without causing alterations in hematological, renal, hepatic or coagulation tests after 30 days of treatment. However, both drugs induced chronic gastritis

Short communication: Application of site‐level assessment of governance and equity (sage) methodology to a candidate oecm: AndakÍ municipal natural park, caquetÁ, colombia.

Governance is a fundamental aspect and precondition for conservation strategies, such as protected areas or OECMs. A methodology for Site-level Assessment of Governance and Equity (SAGE) has been proposed by IUCN to explore different aspects of governance, based on ten principles. This article describes the application of SAGE to a candidate OECM for what we believe is the first time: the Andakí Municipal Natural Park in the Amazon region of Colombia. The application of SAGE generated useful insights into different aspects of governance, including the importance of good communication and recognising and respecting the rights and responsibilities of different actors. Based on this experience, we believe that the SAGE methodology could be a useful tool not only to identify priorities for improving governance, but also to assess governance and equity in order to evaluate if an area meets the criteria for an OECM that it is governed and managed to achieve sustained and effective contributions to in situ conservation of biodiversity, associated ecosystem functions and services, and cultural, spiritual, socio-economic and other locally relevant values. © 2021, IUCN - International Union for the Conservation of Nature. All rights reserved.This process was made possible with the support of: a) the Local Protected Areas Regional Project implemented by Deutsche Gesellschaft f?r Internationale Zusammenarbeit (GIZ) GmbH, ICLEI ? Local Governments for Sustainability and the International Union for Conservation of Nature (IUCN); Environment ministries in Brazil, Colombia, Ecuador and Peru; commissioned by the German Federal Ministry for the Environment, Nature Protection and Nuclear Safety; b) the project adaptation of the OECM criteria to the Colombian context supported by PPD-GEF-PNUD, and implemented by Resnatur, Instituto Humboldt, Fundaci?n Natura and the Local Protected Areas Project; and c) the EUROCLIMA+ programme supported by Expertise France, GIZ and the International Institute for the Environment and Development (IIED); and d) Thora Amend, Vice Chair, IUCN World Commission on Protected Areas (thematic area: Governance)