Mastitis bovina de orígen micótico: descripción de un caso.

El estudio se realizó en una hacienda ubicada en un municipio de Cundinamarca a una altitud de 340 metros y una temperatura promedio de 26 grados centígrados, con 185 animales de la raza Pardo Suizo y mestizo (Pardo Suizo x Cebú) de los cuales 105 estaban en producción de leche y los demás estaban en el horro o en proceso de cría y levante. Se practicó una visita a la finca para evaluar y diagnosticar un brote de mastitis que afectaba a 63 animales del hato en forma clínica aguda. Se realizó un chequeo general con la prueba de mastitis california (MC) en todos los animales del hato dando un resultado positivo en 148 cuartos de 68 vacas. Se procedió a tratar a los animales afectados con productos antibacterianos pero con resultados negativos. Posteriormente se tomaron muestras de secreciones de los cuartos afectados que se cultivaron en agar sangre al 5 por ciento con incubación a 37 grados centígrados por 72 horas, agar sabouraud incubado a 28 grados centígrados por 4 días y agar MacConkey a 37 grados centígrados por 72 horas. Los resultados microbiológicos e histopatológicos definen el diagnóstico de mastitis micótica. Establecido el carácter micótico de la enfermedad, se suspendió todo producto antibacteriano y se inició una terapia para atacar al hongo. Una vez terminado el tratamiento se hizo notoria la recuperación clínica y productiva en 50 animales. Los 13 restantes desarrollaron un estado de fibrosis de la glándula mamaria que obligó a su eliminación Para buscar el origen de la infección se examinó el antibiótico y las sondas plásticas empleadas en el tratamiento. Descartada la fuente de contaminación en el antibiótico y en las sondas la misma se puede atribuír al agua utilizada durante los tratamientos como diluyenteGanado de leche-Ganadería lech

Estudio microbiológico durante el faenado, transporte, almacenamiento y procesamiento de canales bovinas.

Se estudian microbiológicamente 10 canales bovinas tomadas al azar durante el faenado, almacenamiento, transporte y deshuese a cortes mayoristas de un total de 35 animales sacrificados en Villavicencio, Colombia y transportados 126 km en cuartos de canal en carros aislados no refrigerados para su deshuese y consumo en Bogotá. Fueron recolectadas muestras de los equipos utilizados para conocer su importancia como contaminantes. De cada canal se tomaron 4 muestras, 2 de los cuartos posteriores y 2 de los anteriores. Todas las muestras recolectadas se analizaron para recuento total de bacterias mesofílicas aerobias, coliformes y psicrofílicas/cm2. El análisis estadístico demuestra coeficientes de regresión simple altamente significativos entre tiempo y bacterias mesófilicas totales y coliformes y entre tiempo y bacterias psicrofílicas. No hubo diferencias significativas entre la temperatura y los recuentos en las diferentes clases de bacterias estudiadas. Los equipos utilizados durante el proceso fueron altamente contaminantes (paredes y pisos de carros, mesas y cuchillos de deshuese, bancos). Se encontró mayor contaminación en los cuartos anteriores que en los posterioresGanado de leche-Ganadería lech

Respuesta humoral a rinotraqueitis infecciosa bovina evaluada por seroneutralización e inmunodifusión en ganado lechero vacunado.

En Colombia el aislamiento y las evidencias serológicas sobre el virus de la rinotraqueitis infecciosa bovina (RIB o IBR), así como las manifestaciones clínicas e histopatológicas compatibles justifican su estudio. En este trabajo se siguió la evolución de los anticuerpos séricos a RIB y se observó el comportamiento clínico de una población bovina mayor de 6 meses, después de vacunación. Se buscó con esto conocer a nivel de campo el grado de protección conferido por los anticuerpos y simultáneamente la posibilidad de utilización de la inmunodifusión doble (IDD) como prueba tamiz con respecto a la tradicional seroneutralización (SN). Un total de 150 bovinos de una explotación lechera de la sabana de Bogotá (Colombia), fueron estudiados en su producción de anticuerpos humorales durante 16 meses por las técnicas de seroneutralización e inmunodifusión después de vacunación a virus vivo modificado, vía intranasal. Se detectó elevación significativa (p menor o igual que 0.05) de títulos neutralizantes a la primera sangría post-vacunación. Los títulos en general se mantuvieron elevados hasta el cuarto mes, tiempo en el cual empezaron a descender hasta alcanzar niveles significativamente más bajos (p menor o igual que 0.05) que los valores iniciales, observándose simultáneamente una baja protección a la infección respiratoria. La evaluación de los sueros por las técnicas de seroneutralización e inmunodifusión permitió corroborar la confiabilidad de la inmunodifusión como prueba de selección para reactores positivos. Se analizaron factores de especificidad y sensibilidad la mismaGanado de leche-Ganadería lech

Kinetic Energy-induced Growth Regimes of Nanocolumnar Ti Thin Films Deposited by Evaporation and Magnetron Sputtering

We experimentally analyze different growth regimes of Ti thin films associated to the existence of kinetic energy-induced relaxation mechanisms in the material's network when operating at oblique geometries. For this purpose, we have deposited different films by evaporation and magnetron sputtering under similar geometrical arrangements and at low temperatures. With the help of a well-established growth model we have found three different growth regimes: (i) low energy deposition, exemplified by the evaporation technique, carried out by species with typical energies in the thermal range, where the morphology and density of the film can be explained by solely considering surface shadowing processes, (ii) magnetron sputtering under weak plasma conditions, where the film growth is mediated by surface shadowing mechanisms and kinetic-energy-induced relaxation processes, and (iii) magnetron sputtering under intense plasma conditions, where the film growth is highly influenced by the plasma, and whose morphology is defined by nanocolumns with similar tilt than evaporated films, but with much higher density. The existence of these three regimes explains the variety of morphologies of nanocolumnar Ti thin films grown at oblique angles under similar conditions in the literature.EU-FEDER and MINECO-AEI 201560E055EU-FEDER and MINECO-AEI MAT2014-59772-C2-1-PEU-FEDER and MINECO-AEI MAT2016-79866-REU-FEDER and MINECO-AEI MAT2015-69035-REDCUniversity of Seville V and VI PPIT-U

Nanostructured Ti thin films by magnetron sputtering at oblique angles

The growth of Ti thin films by the magnetron sputtering technique at oblique angles and at room temperature is analysed from both experimental and theoretical points of view. Unlike other materials deposited in similar conditions, the nanostructure development of the Ti layers exhibits an anomalous behaviour when varying both the angle of incidence of the deposition flux and the deposition pressure. At low pressures, a sharp transition from compact to isolated, vertically aligned, nanocolumns is obtained when the angle of incidence surpasses a critical threshold. Remarkably, this transition also occurs when solely increasing the deposition pressure under certain conditions. By the characterization of the Ti layers, the realization of fundamental experiments and the use of a simple growth model, we demonstrate that surface mobilization processes associated to a highly directed momentum distribution and the relatively high kinetic energy of sputtered atoms are responsible for this behaviourJunta de Andalucía P12-FQM- 2265Ministerio de Ciencia e Innovación CSD2008- 00023, MAT2013-42900-P, MAT2013-40852-R, MAT2014-59772-C2-1, MAT2011- 2908

Theoretical and experimental characterization of TiO2 thin films deposited at oblique angles

The microstructural features of amorphous TiO2 thin films grown by the electron beam physical vapour deposition technique at oblique angles have been experimentally and theoretically studied. The microstructural features of the deposited films were characterized by considering both, the column tilt angle and the increase of the column thickness with height. A Monte Carlo model of the film growth has been developed that takes into account surface shadowing, short-range interaction between the deposition species and the film surface, as well as the angular broadening of the deposition flux when arriving at the substrate. The good match between simulations and experimental results indicates the importance of these factors in the growth and microstructural development of thin films deposited at oblique angles.Ministerio de Innovación, MAT 2007-65764, CONSOLIDER INGENIO 2010-CSD2008-00023, PIE 200960I132Junta de Andalucía TEP2275, TEP5283, P07-FQM-03298, FQM-690

Nanocolumnar growth of thin films deposited at oblique angles: Beyond the tangent rule

The growth of nanostructured physical vapor deposited thin films at oblique angles is becoming a hot topic for the development of a large variety of applications. Up to now, empirical relations, such as the so-called tangent rule, have been uncritically applied to account for the development of the nanostructure of these thin films even when they do not accurately reproduce most experimental results. In the present paper, the growth of thin films at oblique angles is analyzed under the premises of a recently proposed surface trapping mechanism. The authors demonstrate that this process mediates the effective shadowing area and determines the relation between the incident angle of the deposition flux and the tilt angle of the columnar thin film nanostructures. The analysis of experimental data for a large variety of materials obtained in our laboratory and taken from the literature supports the existence of a connection between the surface trapping efficiency and the metallic character of the deposited materials. The implications of these predictive conclusions for the development of new applications based on oblique angle deposited thin films are discussed.Junta de Andalucía P09-CTS- 5189, TEP5283, FQM-6900Ministerio de Ciencia e Innovación CSD2008-00023, MAT2010-21228, MAT2010-1844

Nanocolumnar growth of thin films deposited at oblique angles: Beyond the tangent rule

The growth of nanostructured physical vapor deposited thin films at oblique angles is becoming a hot topic for the development of a large variety of applications. Up to now, empirical relations, such as the so-called tangent rule, have been uncritically applied to account for the development of the nanostructure of these thin films even when they do not accurately reproduce most experimental results. In the present paper, the growth of thin films at oblique angles is analyzed under the premises of a recently proposed surface trapping mechanism. The authors demonstrate that this process mediates the effective shadowing area and determines the relation between the incident angle of the deposition flux and the tilt angle of the columnar thin film nanostructures. The analysis of experimental data for a large variety of materials obtained in our laboratory and taken from the literature supports the existence of a connection between the surface trapping efficiency and the metallic character of the deposited materials. The implications of these predictive conclusions for the development of new applications based on oblique angle deposited thin films are discussed. © 2014 American Vacuum Society.Peer Reviewe

Growth of nanocolumnar thin films on patterned substrates at oblique angles

The influence of one dimensional substrate patterns on the nanocolumnar growth of thin films deposited by magnetron sputtering at oblique angles is theoretically and experimentally studied. A well‐established growth model has been used to study the interplay between the substrate topography and the thin film morphology. A critical thickness has been defined, below which the columnar growth is modulated by the substrate topography, while for thicknesses above, the impact of substrate features is progressively lost in two stages; first columns grown on taller features take over neighboring ones, and later the film morphology evolves independently of substrate features. These results have been experimentally tested by analyzing the nanocolumnar growth of SiO2 thin films on ion‐induced patterned substrates.University of Seville: V PPIUSUniversity of Seville: VI PPIT-USEuropean Development Funds program (EU-FEDER) / Spanish Ministry of Economy and Competitiveness and Agencia Estatal de Investigación (AEI) : MAT2013-40852-REuropean Development Funds program (EU-FEDER) / Spanish Ministry of Economy and Competitiveness and Agencia Estatal de Investigación (AEI) : MAT2016- 79866-REuropean Development Funds program (EU-FEDER) / Spanish Ministry of Economy and Competitiveness and Agencia Estatal de Investigación (AEI) : MAT2015-69035-REuropean Development Funds program (EU-FEDER) / Spanish Ministry of Economy and Competitiveness and Agencia Estatal de Investigación (AEI) : MAT2015-69035-REDCEuropean Development Funds program (EU-FEDER) / Spanish Ministry of Economy and Competitiveness and Agencia Estatal de Investigación (AEI) : MAT2017-85089-C2-1- RComunidad Autónoma de Madrid S2013/MIT-3029Comunidad Autónoma de Madrid IND2017/IND766

Theoretical and experimental characterization of TiO2 thin films deposited at oblique angles

The microstructural features of amorphous TiO2 thin films grown by the electron beam physical vapour deposition technique at oblique angles have been experimentally and theoretically studied. The microstructural features of the deposited films were characterized by considering both the column tilt angle and the increase in the column thickness with height. A Monte Carlo model of film growth has been developed that takes into account surface shadowing, short-range interaction between the deposition species and the film surface, as well as the angular broadening of the deposition flux when arriving at the substrate. The good match between simulations and experimental results indicates the importance of these factors in the growth and microstructural development of thin films deposited at oblique angles. © 2011 IOP Publishing Ltd.Peer Reviewe