Conductividad eléctrica en función de la temperatura de compuestos de 3YTZP con nano-plaquetas de grafeno

En este proyecto se ha estudiado la conductividad eléctrica y su dependencia con la temperatura en compuestos cerámicos de circona con 3%mol de itria (3YTZP, Yttria Tetragonal Zirconia Polycrystals) con tres contenidos distintos de nano-plaquetas de grafeno (GNPs, Graphene Nano Platelets), todas ellas (5, 10, 20%vol. de GNPs), por encima del límite de percolación eléctrica. Estos compuestos fueron sometidos a presión uniaxial durante la sinterización, por lo que el estudio se ha realizado en dos direcciones: la perpendicular y la paralela al eje de presión durante sinterización. En primer lugar, se ha realizado un análisis de la conductividad eléctrica a temperatura ambiente de estos compuestos donde se ha puesto de manifiesto la anisotropía eléctrica de los compuestos, reflejada en el factor de anisotropía eléctrica . La dependencia de la conductividad eléctrica con el contenido de GNPs se ha modelado mediante la regla de las mezclas obteniéndose un parámetro de conectividad de las fases (n), el cual sólo depende de la dirección en la que se mide la conductividad, siendo independiente de la cantidadde GNPs. En segundo lugar, se ha llevado a cabo el estudio de la conductividad eléctrica en función de la temperatura para estos compuestos mediante espectroscopía de impedancia compleja para determinar los distintos comportamientos (tipo metálico o semiconductor) que poseen los compuestos en función de la cantidad de GNPs y la dirección en la que se mida laconductividad . Se ha obtenido un comportamiento tipo semiconductor en algunos casos y en otros, el comportamiento es de tipo metálico. El comportamiento de tipo semiconductor se ha modelado utilizando el modelo bidimensional de salto de rango variable (2D-VRH, Two Dimensional Variable Range Hopping). Finalmente, haciendo uso de la espectroscopía Raman se ha puesto de manifiesto que no se han producido daños estructurales en las GNPs al someterlas a altas temperaturas (hasta 450℃). Haciendo un estudio de las bandas características de los espectros se ha puesto de manifiesto la anisotropía estructural de los compuestos, indicando una mayor cantidad de defectos en las secciones transversales de los compuestos .Universidad de Sevilla. Grado en Físic

Perfil fitoquímico, actividad antimicrobiana y antioxidante de extractos de Gnaphalium oxyphyllum y Euphorbia maculata nativas de Sonora, México

The use of synthetic chemical compounds to preserve foods or treat diseases of bacterial origin is limited because they can cause health damage. Therefore, the food and livestock industries seek natural strategies to preserve foods and preserve the health of animals intended for human consumption. In this sense, some extracts of plant from Sonora, Mexico could be an alternative due to the great diversity of plants and the fact that some of them are traditionally used to treat diseases. On the other hand, there are few studies that support the biological activity of ethanolic extracts of Gnaphalium oxyphyllum (E1) and Euphorbia maculata (E2). In this study, phytochemical content was determined by spectrophotometry, antimicrobial activity was determined by agar diffusion and antioxidant activity was evaluated by ABTS, DPPH and FRAP. The results showed that the E1 and E2 extracts had total phenols, total flavonoids, flavones and flavonols, total flavanones and dihydroflavonols, as well as total tannins, total chlorogenic acid and total polysaccharides. In addition, both extracts showed higher antimicrobial activity against Listeria monocytogenes ATCC 19115, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Salmonella enterica serovar Typhimurium ATCC 14028 when 1 mg ml-1 was used (P<0.05). In addition, they presented antioxidant activity by the methods of ABTS, DPPH and FRAP. Therefore, the antimicrobial and antioxidant potential of these plants represents a natural alternative to control some Gram-positive and Gram-negative bacteria in the livestock industry, as well as for food preservation.El uso de compuestos químicos sintéticos para conservar alimentos o tratar enfermedades de origen bacteriano está limitado debido a que pueden ocasionar daños en la salud. Por ello, las industrias alimentaria y pecuaria buscan estrategias naturales para conservar alimentos y mantener la salud de los animales destinados a consumo humano. En este sentido, algunos extractos de plantas provenientes de Sonora, México podrían ser una alternativa debido a la gran diversidad de plantas y que algunas de ellas se utilizan tradicionalmente para tratar enfermedades. Por otro lado, son pocos los estudios que sustentan la actividad biológica de los extractos etanólicos de Gnaphalium oxyphyllum (E1) y Euphorbia maculata (E2). En este estudio, el contenido de fitoquímicos se determinó por espectrofotometría, la actividad antimicrobiana se determinó por difusión en agar y la actividad antioxidante se evaluó por ABTS, DPPH y FRAP. Los resultados mostraron que los extractos E1 y E2 presentaron fenoles totales, flavonoides totales, flavonas y flavonoles, flavanonas y dihidroflavonoles totales, así como, taninos totales, ácido clorogénico total y polisacáridos totales. Además, ambos extractos mostraron mayor actividad antimicrobiana contra Listeria monocytogenes ATCC 19115, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 y Salmonella entérica serovar Typhimurium ATCC 14028 cuando se utilizó 1 mg ml-1 (P<0.05). Además, presentaron actividad antioxidante por los métodos de ABTS, DPPH y FRAP. Por lo anterior, el potencial antimicrobiano y antioxidante de estas plantas representa una alternativa natural para controlar algunas bacterias Gram positivas y Gram negativas en la industria pecuaria, así como para la conservación de alimentos

Productive and technological characteristics of goat farmers in Comondú, Baja California Sur

Objective: Identifying productive characteristics through technological indicators adopted by goat farmers in the municipality of Comondú in Baja California Sur Design/methodology/approach: A questionnaire with semi-structured questions was designed to obtain multicriteria information on variables of technological, economic, social and multilevel indicators. To determine the sample size, the formula suggested by (Snedecor and Cochran, 1967 and cited by Rojas, 1979) was used; Cadena, (2004); Uzcaga, et al., (2021). It indicates that the elements must be selected through a random lottery with replacement for the case of producers representing each UPF, who intervene in PRODETER and according to the numerical characteristics of the universe of producers. Results: The production units (UP) were classified by means of the statistical method of analysis of means conglomerates with SAS, which allowed to identify four groups of producers with 10.33, 69, 10.33 and 10.33% of them. The social indicator showed differences between PUs in the level of education, the non-inclusion of women in the activity, total annual income and whether or not they are integrated in an association. The technological indicator showed differences in the distance of the UP with the community, road conditions, area of the UP, available area for planting, water sources, herd size, availability of facilities, machinery and equipment. The economic indicator showed differences between PU in complementary agricultural activities, economic dependence of the activity, milk production, cheese, waste animals, goat production and their respective sales values. Findings/conclusions: The technological indexes, herd size and distance from the UP to the municipal head and community allowed to group and better understand the producers based on their social characteristics, technological and economic indicators. This information will make it possible to precisely define the type of intervention on management practices or management required.To identify productive characteristics through the technological indicators adopted by goats farmers at theComondú municipality, state of Baja California Sur, Mexico. A survey consisting of semi-structured questionswas designed to obtain multi-criteria information on the variables of technological, economic, social, andmultilevel indicators. The production units (PUs) were classified by the cluster analysis of means statisticalmethod in the SAS software, allowing to identify four groups of producers of 10.33, 69, 10.33, and 10.33 % ofthem. The social indicator demonstrated differences between UPs regard their education level, non-inclusionof women in the activity, total annual income, and whether or not they are members of an association. Thetechnological indicator revealed differences in their distance from the UPs to the community, road conditions,area of the UP, available area for planting, water sources, herd size, availability to facilities, machinery, andequipment. The economic indicator showed differences between UPs in their agricultural complementaryactivities, economic dependence, milk production, cheese production, animal wastes, goat production, andtheir respective sales values. The conclusion is that this information is useful for particularly attending to theneeds and will allow defining the precise kind of intervention in the management practices or the requiredmanagement

Synthesis and atypical antipsychotic profile of some 2-(2-piperidinoethyl)benzocycloalkanones as analogues of butyrophenone

Four new 2-(2-piperidinoethyl)benzocycloalkanone derivatives, 20-23, were prepared and evaluated as potential antipsychotic agents in receptor binding assays for dopamine (DA) and 5-HT2A receptors and in functional and behavioral screens. Their affinities for D2 receptors (Ki's in the nanomolar range: 46.7-70.7) and D1 receptors (Ki's in the micromolar range: 1.09-2.81) were slightly lower than that showed by haloperidol (Ki's in the nanomolar range: 5.01 and 97.72 for D2 and for D1 receptors, respectively). The ratio of pKi's values D1/D2 showed that the new molecules are more D2-selective than haloperidol. In contrast, in the [3H]-ketanserin binding assays the new compounds had greater affinity for 5-HT2A receptors (pKi's 7.89-8.60) than haloperidol (pKi 7.70) and in functional studies, endothelium-stripped aorta rings, the pA2 values (6.75-8.12) were slightly lower than that of ketanserin (8.87) in suppresing serotonin-induced contractions. The pKi's for D2 binding (and to a lesser extent pKi's for D1 binding) tend to be greater among typical (classical) than among atypical antipsychotics, while these two classes of antipsychotics exhibit no difference with regard to pKi's for 5-HT2A receptors. The ratios of pKi's for 5-HT2A/D2 receptors may be useful for rapid screening of new compounds, and its potential induction of extrapyramidal symptoms (ratio values >1.12 were predictive of an atypical antipsychotic profile). The new molecules had a ratio value in the range 1.08-1.20, while haloperidol showed a ratio of 0.93. In the behavioral screening tests, the new molecules showed antagonist activity of amphetamine-inducing hyperactivity and apomorphine-induced climbing (predictive tests for antipsychotic activity). In the catalepsy test (predictive test for induction of extrapyramidal symptoms), the values obtained were in accordance with an atypical antipsychotic drugs profile. © 1994 American Chemical Society.Peer Reviewe

Evaluation of Anxiety Levels in Patients Undergoing Intravitreal Injections and Associated Risk Factors Related to the Disease

Purpose. To analyze patients’ anxiety levels using the Visual Analog Scale for Anxiety (VASA), in regard to intravitreal injection treatment and to determine possible associated risk factors related to the disease and treatment characteristics. Methods. Cross-sectional observational study with consecutive sampling of patients who were going to receive an intravitreal injection. Subjects completed the VASA prior to the procedure, and afterwards, their data were collected from the electronic medical history. Analysis was performed through a linear regression model. Results. Fifty-five men and forty-seven women were enrolled. The mean age was 73.9 ± 12.4 years (mean ± standard deviation (SD)), and the mean ± SD of previous injections was 12.8 ± 12. The most frequent pathologies found were age-related macular degeneration with 46.1% and diabetic macular edema with 36.3%. The median of anxiety levels measured in millimeters (mm) was 16 (interquartile range: 0–48). In univariate models, women presented a mean of 10.8 mm of anxiety more than men (p=0.03). The adjusted multivariate analysis demonstrated that younger patients declared higher anxiety levels (p=0.036). No significant association was found between the best corrected visual acuity (BCVA) on the day of the injection, the change in BCVA since the beginning of the treatment or the number of injections received, and the registered anxiety levels. Conclusions. Sex and age may have an influence on anxiety levels. BCVA and the number ofinjections received did not seem to have an influence on our patients anxiety levels

Informe CCe 2016. Cultura científica, percepción y actitudes ante la ciencia y la innovación en el sector empresarial español

145 páginasSe presentan los resultados de la encuesta 'Cultura Científica Empresarial en España 2016' (Cultura científica, percepción y actitudes ante la ciencia y la innovación en el sector empresarial español), realizada a un conjunto de informantes constituido por empresarios/as y personas con cargos directivos en una muestra representativa de las empresas españolas. Partiendo de la hipótesis de que la percepción de la ciencia y la innovación, y la cultura científica empresarial en general, pueden influir de manera determinante en comportamientos clave de la empresa, relacionados con sus actividades innovadoras, el proyecto ‘Cultura Científica Empresarial tiene como objetivo examinar aquellas variables subjetivas y culturales que influyen en las actividades del sector empresarial en materia de I+D e innovación y en su comportamiento innovador. Se pretende estudiar cuál es la percepción de la ciencia, la tecnología y la innovación en el sector empresarial y cuáles son las actitudes y motivaciones de las empresas españolas hacia la financiación y ejecución de la I+D y la innovación (tanto interna como en cooperación con el sector público) así como los principales obstáculos para la apropiación de conocimiento científico. El proyecto parte de la constatación de los límites de los enfoques economicistas –desconsideración de variables contextuales e históricas, racionalización excesiva de los procesos de transferencia de conocimiento– que ponen de manifiesto la necesidad de estudiar el vínculo ciencia-empresa como relación social. Se propone una posible complementariedad teórica con el enfoque de los estudios de percepción pública de la ciencia, capaz de solucionar dichas carencias mediante la atención a aspectos tales como factores culturales, valores políticos y sociales, la confianza institucional o la percepción del riesgo.Estudio financiado por el Ministerio de Economía y Competitividad. Plan Estatal de Investigación Científica y Técnica y de Innovación. Proyecto CSO2014-53293-RN