Do oral biofilms influence the wear and corrosion behavior of titanium?

The main aim of this work was to study the simultaneous wear-corrosion of titanium (Ti) in the presence of biofilms composed of Streptococcus mutans and Candida albicans. Both organisms were separately grown in specific growth media, and then mixed in a medium supplemented with a high sucrose concentration. Corrosion and tribocorrosion tests were performed after 48 h and 216 h of biofilm growth. Electrochemical corrosion tests indicated a decrease in the corrosion resistance of Ti in the presence of the biofilms although the TiO2 film presented the characteristics of a compact oxide film. While the open circuit potential of Ti indicated a tendency to corrosion in the presence of the biofilms, tribocorrosion tests revealed a low friction on biofilm covered Ti. The properties of the biofilms were similar to those of the lubricant agents used to decrease the wear rate of materials. However, the pH-lowering promoted by microbial species, can lead to corrosion of Ti-based oral rehabilitation systems.

Wear and Corrosion Interactions on Titanium in Oral Environment: Literature Review

The oral cavity is a complex environment where corrosive substances from dietary, human saliva, and oral biofilms may accumulate in retentive areas of dental implant systems and prostheses promoting corrosion at their surfaces. Additionally, during mastication, micromovements may occur between prosthetic joints causing a relative motion between contacting surfaces, leading to wear. Both processes (wear and corrosion) result in a biotribocorrosion system once that occurs in contact with biological tissues and fluids. This review paper is focused on the aspects related to the corrosion and wear behavior of titanium-based structures in the oral environment. Furthermore, the clinical relevance of the oral environment is focused on the harmful effect that acidic substances and biofilms, formed in human saliva, may have on titanium surfaces. In fact, a progressive degradation of titanium by wear and corrosion (tribocorrosion) mechanisms can take place affecting the performance of titanium-based implant and prostheses. Also, the formation of wear debris and metallic ions due to the tribocorrosion phenomena can become toxic for human tissues. This review gathers knowledge from areas like materials sciences, microbiology, and dentistry contributing to a better understanding of bio-tribocorrosion processes in the oral environment.

Yuca ensilada como fuente de energía para cerdos en crecimiento

Se condujeron dos experimentos para determinar el comportamiento de cerdos en crecimiento, comparando la dieta de maíz-soya con otra de raíz de yuca ensilada con agua o vinaza. Se utilizaron 16 cerdos de cruce comercial alojados en corrales individuales, mediante clasificación simple y dos tratamientos con ocho repeticiones/ tratamiento. En el segundo trabajo se utilizaron 16 animales en similares condiciones, con vinaza para ensilar. No fueron encontradas diferencias significativas para la ganancia diaria (g) y conversión alimentaria (kg kg-1). Se concluye que la raíz de yuca ensilada con agua y yogurt o vinaza, puede sustituir totalmente la energía del maíz para cerdos en crecimiento.

Consumption Diagnosis of Sweet Cassava in three Municipalities in Cuba

Cassava is an important staple food for human and animal feeding in Cuba. Despite its importance, there is little or nonexistent information to diagnose preferences and frequency of consumption of cassava in that country. In this sense, the present article characterizes the preferences and frequency of consumption of cassava in the municipalities of Plaza de la Revolución-La Habana province, El Salvador–Guantanamo province and San José de Las Lajas–Mayabeque province in Cuba. A survey was conducted through a questionnaire containing twelve closed and two open questions. The sample was determined based on the number of total population of each municipality considering 95% as confidence interval and 5% as error margin. The results were statistically analyzed by calculating the absolute and the relative frequencies of each question. It was observed that the acquisition of cassava in the municipalities of Plaza de la Revolución, El Salvador and San José de las Lajas in Cuba is done by purchase small quantities of fresh cassava for home consumption within one week, due to the extreme perishability of cassava, which limits consumers' ability to store fresh roots at home. The choice of cassava is made based on both skin colour (light brown) and pulp (white) and empirical knowledge about its ease of cooking, and that cassava is mostly consumed in boiled and fried forms up to four times a week in times where there is root market supply with the desirable culinary characteristics (cooking facility), that is, from September to December.

Pruning management of cassava for animal feeding: parameters of the root

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dynamic Range of Vertebrate Retina Ganglion Cells: Importance of Active Dendrites and Coupling by Electrical Synapses

The vertebrate retina has a very high dynamic range. This is due to the concerted action of its diverse cell types. Ganglion cells, which are the output cells of the retina, have to preserve this high dynamic range to convey it to higher brain areas. Experimental evidence shows that the firing response of ganglion cells is strongly correlated with their total dendritic area and only weakly correlated with their dendritic branching complexity. On the other hand, theoretical studies with simple neuron models claim that active and large dendritic trees enhance the dynamic range of single neurons. Theoretical models also claim that electrical coupling between ganglion cells via gap junctions enhances their collective dynamic range. In this work we use morphologically reconstructed multi-compartmental ganglion cell models to perform two studies. In the first study we investigate the relationship between single ganglion cell dynamic range and number of dendritic branches/total dendritic area for both active and passive dendrites. Our results support the claim that large and active dendrites enhance the dynamic range of a single ganglion cell and show that total dendritic area has stronger correlation with dynamic range than with number of dendritic branches. In the second study we investigate the dynamic range of a square array of ganglion cells with passive or active dendritic trees coupled with each other via dendrodendritic gap junctions. Our results suggest that electrical coupling between active dendritic trees enhances the dynamic range of the ganglion cell array in comparison with both the uncoupled case and the coupled case with cells with passive dendrites. The results from our detailed computational modeling studies suggest that the key properties of the ganglion cells that endow them with a large dynamic range are large and active dendritic trees and electrical coupling via gap junctions.

Influence of Osmotic Dehydration on Ascorbic Acid Loss in Pickled Dry Peppers (Capsicum chinense)

The objective of this work was (1) to develop a dehydrated pepper with 45% humidity, determining the drying curves for pepper, with and without osmotic pre-treatment and (2) to evaluate the influence of both drying and osmotic treatment on the content ascorbic acid (vitamin C) in fresh pepper and pepper with 45% humidity. The experiments were carried out using the peppers cut in half, with and without osmotic pre-treatment, followed by drying in an oven at 70 degrees C. The results showed that the osmotic pretreatment did not influence the retention of ascorbic acid during the drying of pepper. The sensory analysis regarding the color, flavor, and texture attributes revealed that there was no difference in the acceptability.

Influence of osmotic dehydration on ascorbic acid loss in pickled dry peppers (Capsicum chinense)

The objective of this work was (1) to develop a dehydrated pepper with 45% humidity, determining the drying curves for pepper, with and without osmotic pre-treatment and (2) to evaluate the influence of both drying and osmotic treatment on the content ascorbic acid (vitamin C) in fresh pepper and pepper with 45% humidity. The experiments were carried out using the peppers cut in half, with and without osmotic pre-treatment, followed by drying in an oven at 70 ºC. The results showed that the osmotic pretreatment did not influence the retention of ascorbic acid during the drying of pepper. The sensory analysis regarding the color, flavor, and texture attributes revealed that there was no difference in the acceptability.

Effects of thyroid status on NEI concentration in specific brain areas related to reproduction during the estrous cycle

We previously showed that short-term hypo- and hyperthyroidism induce changes in neuropeptide glutamic-acid-isoleucine-amide (NEI) concentrations in discrete brain areas in male rats. To investigate the possible effects of hypo- and hyperthyroidism on NEI concentrations mainly in hypothalamic areas related to reproduction and behavior, female rats were sacrificed at different days of the estrous cycle. Circulating luteinizing hormone (LH), estradiol and progesterone concentrations were measured in control, hypothyroid (hypoT, treated with PTU during 7-9 days) and hyperthyroid (hyperT, l-T4 during 4-7 days) animals. Both treatments blunted the LH surge. Hypo- and hyperthyroidism increased estradiol concentrations during proestrus afternoon (P-PM), although hypoT rats showed lower values compared to control during proestrus morning (P-AM). Progesterone levels were higher in all groups at P-PM and in the hyperT during diestrus morning (D2). NEI concentrations were lower in hypoT rats during the estrous cycle except in estrus (E) in the peduncular part of the lateral hypothalamus (PLH). They were also reduced by both treatments in the perifornical part of the lateral hypothalamus (PeFLH) during P-PM. Hypothyroidism led to higher NEI concentrations during P-PM in the organum vasculosum of the lamina terminalis and anteroventral periventricular nucleus (OVLT+AVPV). The present results indicate that NEI concentration is regulated in a complex manner by hypo- and hyperthyroidism in the different areas studied, suggesting a correlation between NEI values and the variations of gonadal steroid levels during estrous cycle. These changes could be, in part, responsible for the alterations observed in the hypothalamic-pituitary-gonadal axis in these pathologies.

Respuesta ecofisiológica a la temperatura y radiación de la especie Cystoseira tamariscifolia recolectada en el Sur de España

Programa de Doctorado en Ciencias del Mar, Laboratorio de Botánica, Facultad de Farmacia, Universidad de Barcelona, Barcelona, España. Departamento de Ecología, Universidad de Málaga, Málaga, España

Facebook, YouTube y Blogs como herramientas complementarias en las estrategias de marketing de las agencias de viajes presenciales y online

Estructura de Teleformación

Gli ebrei siciliani

Aus: Nuova Antologia di scienze, lettere ed arti ; Anno 2, Vol. 4.1867

Sulle tipografie ebraiche di Cremona nel secolo XVI : col ragguaglio di un salterio ebraico stamp. in datta città nel sec. medesimo

Cremona, Diss. storico-critico

La memoria literaria de la provincia de Misiones (2ª parte). 16H301

ASISTENCIA A CONGRESOS: 17 TRABAJOS PRESENTADOS. 1- I JORNADAS TEMÁTICAS DE LITERATURA ARGENTINA CONTEMPORÁNEA: EL HUMOR EN LA LITERATURA ARGENTINA. Mendoza, del 25 al 27 de agosto de 2011 Ponencias presentadas: A) El humor de María Elena: infancia, memoria y crítica, María de las Mercedes García Saraví- María Alejandra Viana. B) Una mirada humorística en Dormir al sol, Karina Lemes y Natalia Aldana. C) De los Cambios en tu hijo adolescente a la alienación del ser. Karina Lemes. D) Isidoro Blaisten; el Humor como coartada, elaborado por Marisa Renaut; 2 - II CONGRESO INTERNACIONAL DE LITERATURA Y CULTURA ESPAÑOLAS CONTEMPORÁNEAS. Diálogos transatlánticos 3, 4 y 5 de octubre de 2011. Presentadas las siguientes ponencias: A) Laberintos y zonas de densidad: Barcelona y La Plata en dos novelas policiales de Manuel Vázquez Montalbán y Néstor Ponce. Carolina Repetto Mercedes García Saraví. B) El asedio: eco del mundo novelesco de Arturo Pérez Reverte, Haydée Borowski – Mercedes García Saraví. C) De la metaficción y otros procedimientos en La loca de la casa, Karina Beatriz Lemes. 3– XVI CONGRESO NACIONAL DE LITERATURA ARGENTINA. Resistencia, 6, 7 y 8 de octubre de 2011. Presentadas las siguientes ponencias. A) “Ceviche: una nueva cocina del policial”, María Aurelia Escalada- Mercedes García Saraví. B) Entre Santa María y Ruvichá: mundos ficcionales de Latinoamérica. Jorge Hernando Otero. C) El titirimundi de Juan Enrique Acuña: resignificaciones de un arte menor. Ana Eugenia Kushidonchi - Carina Mabel Pereira. D) Gauna: el hallazgo de un manuscrito, Mara Rabbe. E) Filiaciones en el borde. Lorca y Acuña. Karina Lemes y Natalia Aldana. F) Un Amable trasgresor de los géneros, Gabriela Román. 4- IV JORNADAS NACIONALES DE MINIFICCIÓN: HORIZONTES DE LA BREVEDAD EN EL MUNDO IBEROAMERICANO. HOMENAJE A DAVID LAGMANOVICH (1927-2010) Mendoza. 2, 3 y 4 de noviembre de 2011. Presentadas las siguientes ponencias: A) Falsificaciones, de Marco Denevi: la traducción y el apócrifo, aportes al género microrrelato Gabriela Román y Mercedes García Saraví. B) Formas breves en la narrativa de Hugo Wenceslao Amable, por Gabriela Román. Aceptado para actas. 5- IV CONGRESO CELEHIS, Mar del Plata, 7, 8 y 9 de noviembre 2011. Presentadas las siguientes ponencias. A) De la crítica y otros procedimientos en la Loca de la casa, Karina B. Lemes; b) Trayectorias y fronteras en Cádiz: El asedio (2009) de Arturo Pérez Reverte. Haydée Borowski – Mercedes García Saraví. C) Algunos mundos ficcionales de América Latina. Por Jorge Hernando Otero.// Defensa de Tesinas: Jorge Hernando Otero. Relatos ruvichenses: un espacio misionero/latinoamericano. Directora: Mercedes García Saraví. Codirectora: Karina B. Lemes. Defendida 02/11/2011, Nota: 10 (diez).

Terrorismo : análisis tras el atentado del 11 de setiembre de 2001

El informe nos presenta un análisis del terrorismo y la guerra luego del atentado a las Torres Gemelas el 11 de septiembre del 2001 en EE.UU. Participan el sociológo Raúl Bernal Meza, el dr. en sociología Isidoro Cheresky , y Andrés Repetto, un periodista especializado en política internacional a través de enlace satelital UNCuyo-Buenos Aires. Este último opina sobre los efectos derivados en el mundo luego del atentado, los cambios en las relaciones bilaterales, la modificación de escenarios y los efectos de la globalización.