239 research outputs found
Effect of sintering time on the microstructure and mechanical properties of (Ti,Ta)(C,N)-based cermets
Complete solid-solution cermets based on titanium-tantalum carbonitride using a starting nominal composition with 80 wt.% of (Ti0.8Ta 0.2)(C0.5N0.5) and 20 wt.% of Co were performed by pressure-less sintering at 1550 C for different times (from 0 to 180 min) in an inert atmosphere. Chemical and phase analyses were conducted using X-ray diffraction (XRD), elemental analysis and energy dispersive X-ray spectrometry (EDX). The binder mean free path and the contiguity of the carbonitride particles were used to rationalise the microstructural effects of the mechanical behaviour. Mechanical characterisation included determining the Vickers hardness, the fracture toughness (conventional indentation microfractures, IM), the dynamic Young's modulus (ultrasonic technique), the biaxial strength (ball on three ball) and a detailed fractographic examination. Finally, the experimental findings were combined with a theoretical fracture mechanics analysis to estimate the critical processing flaw sizes. Binder-less carbonitride clusters, pores and coarse carbonitride grains were the main defects observed and were responsible for the fractures.Gobierno de España MAT2011-2298
In vivo antitumor activity of Euphorbia lathyris ethanol extract in colon cancer models
Euphorbia lathyris seeds have been used to treat various medical conditions. We previously reported that
ethanolic extract from the defatted seed of Euphorbia lathyris (EE) (variety S3201) possesses a potent in vitro
antitumor activity against colon cancer (CRC) cell lines. However, the effects of EE on CRC in vivo models and its
possible preventive activity have not been elucidated. The aim of this study is to develop an in vivo study to
corroborate its efficacy. For this purpose, two tumor induction models have been developed. In orthotopic
xenograft model, it has been shown that EE reduces tumor size without hematological toxicity. The ethanolic
extract induced an intense apoptosis in tumors mediated by caspase 3. Using the Azoxymethane/Dextran Sulfate
Sodium model, a reduction of dysplastic polyps has been demonstrated, showing its preventive power.
Furthermore, EE promoted the presence of an eubiotic microbiotal environment in the mucosa of the colon and
induced an increase in antioxidant enzyme activity. This fact was accompanied by a modulation of cytokine
expression that could be related to its protective mechanism. Therefore, although further experiments will be
necessary to determine its applicability in the treatment of CRC, ES could be a new prevention strategy as well as
treatment for this type of tumor, being a powerful candidate for future clinical trials.Spanish Government RTC-2017-6540-1
RTC2019-006870-1Junta de Andalucia P18-TP-1420European Commission AGR145
CTS-107Andalusian Governmen
Adaptation of clinical isolates of Klebsiella pneumoniae to the combination of niclosamide with the efflux pump inhibitor phenyl-arginine-β-naphthylamide (PaβN): co-resistance to antimicrobials
Objectives: To search for new means of combatting carbapenemase-producing strains of Klebsiella pneumoniae by repurposing the anti-helminth drug niclosamide as an antimicrobial agent and combining it with the efflux pump inhibitor (EPI) phenyl-arginine-β-naphthylamide (PaβN).
Methods: Niclosamide and PaβN MICs were determined for six clinical K. pneumoniae isolates harbouring different carbapenemases by broth microdilution and chequerboard assays. Time-kill curves in the presence of each drug alone and in combination were conducted. The viability of bacterial cells in the presence of repetitive exposures at 8 h to the treatment at the same concentration of niclosamide and/or PaβN (adapted isolates) was determined. The acrAB-tolC genes and their regulators were sequenced and quantitative RT-PCR was performed to assess whether the acrA gene was overexpressed in adapted isolates compared with non-adapted isolates. Finally, the MICs of several antimicrobials were determined for the adapted isolates.
Results: Niclosamide and PaβN had synergistic effects on the six isolates in vitro, but adaptation appeared when the treatment was applied to the medium every 8 h, with an increase of 6- to 12-fold in the MIC of PaβN. Sequencing revealed different mutations in the regulators of the tripartite AcrAB-TolC efflux pump (ramR and acrR) that may be responsible for the overexpression of the efflux pump and the adaptation to this combination. Co-resistance to different antimicrobials confirmed the overexpression of the AcrAB-TolC efflux pump.
Conclusions: Despite the synergistic effect that preliminary in vitro stages may suggest, the combinations of drugs and EPI may generate adapted phenotypes associated with antimicrobial resistance that must be taken into consideration
Colon cancer therapy with calcium phosphate nanoparticles loading bioactive compounds from Euphorbia lathyris: In vitro and in vivo assay
Amorphous calcium phosphate nanoparticles (ACP NPs) exhibit excellent biocompatibility and biodegradability
properties. ACP NPs were functionalized with two coumarin compounds (esculetin and euphorbetin) extracted
from Euphorbia lathyris seeds (BC-ACP NPs) showing high loading capacity (0.03% and 0.34% (w/w) for esculetin
and euphorbetin, respectively) and adsorption efficiency (2.6% and 33.5%, respectively). BC-ACP NPs, no toxic
to human blood cells, showed a more selective cytotoxicity against colorectal cancer (CRC) cells (T-84 cells)
(IC50, 71.42 μg/ml) compared to non-tumor (CCD18) cells (IC50, 420.77 μg/ml). Both, the inhibition of carbonic
anhydrase and autophagic cell death appeared to be involved in their action mechanism. Interestingly, in vivo
treatment with BC-ACPs NPs using two different models of CRC induction showed a significant reduction in
tumor volume (62%) and a significant decrease in the number and size of polyps. A poor development of tumor
vasculature and invasion of normal tissue were also observed. Moreover, treatment increased the bacterial
population of Akkermansia by restoring antioxidant systems in the colonic mucosa of mice. These results show a
promising pathway to design innovative and more efficient therapies against CRC based on biomimetic calcium
phosphate NPs loaded with natural products.Spanish GovernmentEuropean Commission PTQ-17-09172
RTC-2017-6540-1
RTI2018-100934-B-I00
RTC2019-006870-1
RYC2016-21042Junta de Andalucia FEDER program P18-TP-1420
A-CTS666-UGR20
B-CTS-122-UGR20
P18-HO-3882
P18-TP-0969Andalusian Government AGR145
FQM-368
CTS-10
Biological Activity of Extracts from Aromatic Plants as Control Agents against Spoilage Molds Isolated from Sheep Cheese
[EN] The aim of this work was to assess the antifungal and antioxidant activity of essential oils and ethanolic extracts from distilled solid by-products from aromatic plants (Artemisia dracunculus, Hyssopus officinalis, Lavandula stoechas, Origanum vulgare and Satureja montana) against 14 fungi strains isolated from sheep cheese and identified at species level using DNA barcoding based on β-tubulin sequence analysis. In addition, capacity of fungi to produce ochratoxin A, patulin, cyclopiazonic acid and sterigmatocystin was analyzed. Of the isolates, 85.7% belonged to Penicillium (P. commune/biforme, P. crustosum) and 14.3% to Aspergillus (A. puulaauensis and A. jensenii), the first time that these Aspergillus species have been found in sheep’s cheese. All P. commune isolates were producers of cyclopiazonic acid, and the two Aspergillus strains produced sterigmatocystin, but the others did not produce any tested mycotoxin. Among the essential oils tested, oregano, savory and tarragon had a significant antifungal activity against all the isolated strains, but no ethanolic extract showed antifungal activity. By contrast, ethanolic extracts showed great potential as antioxidants. The identification of new molds in cheese will help the dairy industry to know more about those molds affecting the sector, and the use of aromatic plants in the control of fungal spoilage could be a suitable alternative to chemical preservatives used in the agri-food industrySIThis research was financially supported by the Spanish National Institute for Agricultural Research and Experimentation (INIA, http://inia.es) by the project RTA2015-00018-C03-0
Using UAV Photogrammetry and Automated Sensors to Assess Aquifer Recharge from a Coastal Wetland
Novel data-acquisition technologies have revolutionized the study of natural systems, allowing the massive collection of information in situ and remotely. Merging these technologies improves the understanding of complex hydrological interactions, such as those of wetland–aquifer systems, and facilitates their conservation and management. This paper presents the combination of UAV technology with water level dataloggers for the study of a coastal temporary wetland linked to an underlying sandy aquifer and influenced by the tidal regime. Wetland morphology was defined using UAV imagery and SfM algorithms during the dry period. The DTM (6.9 cm resolution) was used to generate a flood model, which was subsequently validated with an orthophoto from a wet period. This information was combined with water stage records at 10-min intervals from a network of dataloggers to infer the water balance of the wetland and the transfers to the aquifer. Inflows into the pond were around 6200 m3 (40% direct precipitation over the pond, 60% surface runoff). Outputs equalled the inputs (41% direct evaporation from water surface, 59% transfers into the aquifer). The proposed methodology has demonstrated its suitability to unravel complex wetland–aquifer interactions and to provide reliable estimations of the elements of the water balance21 página
Material híbrido a base de hidróxidos dobles laminares ZnAl con ácido ursodesoxicólico y su evaluación como sistemas de liberación controlada in vitro
Existe una variedad de moléculas biológicamente activas que, por su poca solubilidad y biodisponibilidad no logran tener una buena administración, ni liberación, por ello la búsqueda y estudio de distintos métodos para mejorar estas características, atendiendo a dicha problemática se decide el uso de materiales biohíbridos biocompatibles. El presente trabajo se centró en el estudio del ácido ursodesoxicólico para mejorar características como biodisponibilidad y liberación, intercalándolo en hidróxidos dobles laminares. Esto se realizó por efecto memoria. Posteriormente el material híbrido se encapsuló con biopolímero de carboxilmetilcelulosa y alginato de sodio, tratando de mejorar la protección del material híbrido y su liberación a través de tracto gastrointestinal. La caracterización de estos materiales se llevó a cabo por el método de difracción de rayos X, espectroscopía de infrarrojo por transformada de Fourier, análisis termogravimétrico y microscopía electrónica de barrido. Las pruebas de liberación fueron evaluadas en UV-Vis.There exists a wide active biological molecule that, by its low solubility and bioavailability, do not have a well administration, neither an adequate release, that is why the research and study of different methods to enhance these characteristics, getting into the problem, it is chosen the usage of biocompatible biohybrid materials. The present work is focused on the study of ursodesoxycholic acid to enhance characteristics as its bioavailability and release, intercalating it in laminar double hydroxides. This was made by exploiting memory effect. Later, the hybrid material was encapsulated with a biopolymer, carboxymethilcelullose or sodium alginate, willing to enhance the protection to the hybrid material, and their release through the gastrointestinal tract. The characterization of these materials was performed through X-Ray Diffraction, Fourier Transform Infrared, Thermogravimetric Analysis and Scanning Electron Microscope. The biohybrid release studies were analyzed through UV-vis
Antitumor Effect of the Ethanolic Extract from Seeds of Euphorbia lathyris in Colorectal Cancer
The seeds of Euphorbia lathyris have been used in traditional medicine to treat various
medical conditions. However, neither all of their active biocompounds nor the molecular mechanisms
underlying their therapeutic effects have been described. A new ethanolic extract of defatted flour
from mature seeds of Euphorbia lathyris showed a high total polyphenol content and significant
antioxidant activity. Chromatographic analysis showed that esculetin, euphorbetin, gaultherin, and
kaempferol-3-rutinoside were the most abundant polyphenolic bioactive compounds. Antiproliferative assays showed a high and selective antitumor activity against colon cancer cell lines (T84
and HCT-15). In addition, a significant antiproliferative activity against glioblastoma multiforme
cells was also demonstrated. Its mechanism of action to induce cell death was mediated by the
overexpression of caspases 9, 3, and 8, and by activation of autophagy. Interestingly, a reduction
in the migration capacity of colon cancer cells and a significant antiangiogenic effect on human
umbilical vein endothelial cells were also demonstrated. Finally, the extract significantly reduced the
subpopulations of cancer stem cells. This extract could be the basis to develop new therapeutic strategies for the treatment of colon cancer, although further experiments will be necessary to determine
its in vivo effects.Granada University (project PSE/17/002), Ministerio de
Ciencia e Innovación (project RTC-2017-6540-1) and by the CTS-107 and AGR145 Groups
Evaluación de los parámetros antropométricos en una muestra nacional de adultos mayores mexicanos
The purpose of this study was to describe anthropometric parameters in a population of Mexican older adults (OA). 516 OA (277 women, 239 men) aged ≥ 65 years were interviewed. Anthropometry and a sociodemographic data questionnaire were performed. Means and standard deviations, prevalence (%) and confidence intervals are reported in the results. SPSS v20.0 was used in the statistical analysis. The combined prevalence of overweight and obesity in our population was 77%. The mean WHR values obtained were (0.97 in men and 0.89 in women). Finally, the percentage of fat in men was 30.6% and in women it was 39.8%. The results of this investigation showed significant differences between men and women in most of the anthropometric measures and nutrition indicators. The prevalence of overweight and obesity reported in the Mexican elderly population was higher than that reported in other studies, which shows an important public health problem in Mexican older adults. More studies are needed at the national level on nutritional parameters in the elderly in order to detect cardiovascular risk factors in a timely manner.El propósito de este estudio fue describir los parámetros antropométricos en una población de adultos mayores (AM) mexicanos. Se entrevistó a 516 AM (277 mujeres, 239 hombres) con ≥ 65 años de edad. Se realizó antropometría, y un cuestionario de datos sociodemográficos. En los resultados se reportan medias y desviaciones estándar, prevalencias (%) e intervalos de confianza. En el análisis estadístico se utilizó el SPSS v20.0. La prevalencia conjunta de sobrepeso y obesidad en nuestra población fue de 77%. Los valores medios de Indice Cintura-Cadera obtenidos fueron (0.97 hombres y 0.89 en mujeres). Por último, el porcentaje de grasa en hombres fue 30.6 % y en mujeres fue 39.8 %. Los resultados de esta investigación arrojaron diferencias significativas entre hombres y mujeres en la mayoría de las medidas antropométricas e indicadores de nutrición. La prevalencia de sobrepeso y obesidad reportada en la población mexicana de edad avanzada fue más alta que lo reportado en otros estudios, lo que muestra un importante problema de salud pública en los en adultos mayores mexicanos. Se requieren más estudios a nivel nacional sobre los parámetros nutricionales en AM con el fin de detectar de forma oportuna factores de riesgo cardiovascular.Actividad Física y Deport
Metodología docente y nuevos recursos en Arqueología Prehistórica
La idea ha sido crear un instrumento capaz de albergar información y documentación docente que irá aumentando progresivamente, en función de las necesidades didácticas que puedan ir surgiendo en las asignaturas citadas, y que periódicamente debe ser revisado, por las constantes actualizaciones que sufran los enlaces seleccionados
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