Improved wear performance of ultra high molecular weight polyethylene coated with hydrogenated diamond like carbon

Hydrogenated diamond like carbon (DLCH) thin films were deposited on medical grade ultra high molecular weight polyethylene (UHMWPE) by radio frequency plasma enhanced chemical vapor deposition. The DLCH coating thicknesses ranged from 250 to 700. nm. The substrates were disks made of UHMWPEs typically used for soft components in artificial joints, namely virgin GUR 1050 and highly crosslinked (gamma irradiated in air to 100. kGy) UHMWPEs. Mechanical and tribological properties under bovine serum lubrication at body temperature were assessed on coated and uncoated polyethylenes by means of nano-hardness and ball-on-disk tests, respectively. Morphological features of the worn surfaces were obtained by confocal microscopy and scanning electron microscopy. This study confirms an increase in surface hardness and good wear resistance for coated materials after 24. h of sliding test compared to uncoated polyethylene. These results point out that to coat UHMWPE with DLCH films could be a potential method to reduce backside wear in total hip and knee arthroplasties.Ministerio de Ciencia y Educación MAT2006-12603- C02-01, CSD2008-0002

Cloning and expression of a Saccharomyces cerevisiae RNA-dependent RNA polymerase

RNA-dependent RNA polymerases (RdRp) are ubiquous enzimes  first described in RNA viruses and virus-like elements. In Saccharomyces cerevisiae this enzyme can be found, fused with capsid proteins, encoded by the L-A helper virus-like particle. Replication cycle of L-A is coupled to that of M satellite particle, which confers a killer phenotype to the yeast (Schmitt & Breinig, 2002). RdRp recognizes and replicates ssRNA from both L-A and M virus. RdRp recognizes a 3'-Terminal Recognition Element (3'TRE), a small stem-loop 5 bases from the 3' end (Ribas, Fujimuras, & Wickner, 1994), which can be used as an effective tool for primerless replication of RNA molecules. To gain further insight on the virus-like particle replication mechanism and to evaluate its possible biotechnological application, the present project is focused on cloning the RdRp coding sequence in several different expression vectors and expressing the protein using different Escherichia coli strains as hosts. Once RdRp is efficiently expressed, we will proceed to purify it by affinity chromatography and test the protein activity by replicating full length viral RNA´s and other RNA sequences with or without the 3'TRE sequence. In our communication we will present our advances in cloning, expression, purification and activity of the yeast polymeras

La fijación externa monolateral en el tratamiento de las fracturas femorales del niño: experiencia preliminar en 20 casos

Veinte niños con fracturas femorales diafisarias simples fueron tratados mediante fijación externa con el aparato de Wagner. Once eran niños y 9 niñas, con una edad media de 8 años (3-15). Doce fracturas eran mediodiafisarias, 6 en el tercio proximal y 2 en el tercio distal. La hospitalización media fue de 9 días (5-20). La duración media de fijación externa fue de 61 días. Cinco casos precisaron de algún tratamiento adicional. En 3 pacientes se detectó una infección en el trayecto de los clavos y 1 de ellos necesitó retirada prematura del aparato. La movilidad articular de la rodilla se restableció de modo completo y constante excepto en 1 caso. En los casos seguidos más de 18 meses se observó un hipercrecimiento medio del fémur fracturado de 0,8 cm (0,5- 1,5). No hubo desaxaciones ni malrotaciones. Las ventajas de la fijación externa en el tratamiento de las fracturas femorales del niño incluyen Un mejor control de los fragmentos fracturarlos, una menor hospitalización y un cuidado más fácil y confortable de los pacientes. La infección del trayecto de los clavos parece ser la complicación más seria. En esta serie se detectó una curva de aprendizaje.Twenty children with simple femoral-shaft fractures were treated by monolateral external fixation with the Wagner device. There were 11 boys and 9 girls with a mean age of 8 years (3-15). Twelve fractures were located at the midshaft, 6 at the proximal third, and 2 other at the distal third of the femur. The mean hospital stay was 9 days (5-20). Mean external fixation time was 61 years. In 5 cases, additional methods of treatment were required. Pin tract infection occurred in 3 cases (one needed premature removal of the device). Except for one case, full range of knee motion was usually achieved after treatment. In patients followed for more than 18 months, a mean femoral overgrowth of 0.8 cm (0.5-1.5) was detected. Neither angular deformities nor malrotations were observed. In our experience, the main advantages of external fixation for femoral-shaft fractures in children include less hospitalization time and an easier and more confortable nursing. External fixation allows a better control of the bone fragments, providing an adequate stability. Pin tract infection seems to be the most important drawback. A learning curve was observed in this series

Impact of concurrent pregnancy and lactation on maternal nestbuilding, estradiol and progesterone concentrations in rabbits

[EN] We evaluated the impact of concurrent pregnancy and lactation on: nest-building (i.e., digging, straw-carrying, hair-pulling), food intake, milk output, body weight, and the concentration of estradiol and progesterone in blood. Digging was lower in pregnant-lactating (PL) rabbits, compared with pregnant-only (PO) does, on 21-23 d (52±64 vs. 104±86 g, respectively; mean±SD; P<0.05). Straw-carrying was also reduced in PL does on 24-26 d (9±27 vs. 79±94 g; P<0.005), 27-29 (27±56 vs. 99±77 g; P<0.005), and in the total amount of material introduced into the nest box (132±167 vs. 286±217 g; P<0.02). Hair-pulling was expressed by practically all animals. Food intake declined in PO does on the three days preceding parturition (P<0.01) and increased markedly during lactation; this increase was much larger in PL than in lactating-only (LO) rabbits (P<0.01). Milk output was similar between PL and LO does during the first 21 d of lactation but a marked decline in this parameter occurred in PL does from then until 30 d. The differences in nest-building between PL and PO rabbits may be related to the concentrations of estradiol and progesterone on specific days of pregnancy. PL does showed significantly higher estradiol levels than PO animals on pregnancy 1 d (33±13 vs. 23±4 pg/mL; P<0.02) and 21 (34±19 vs. 24±6 pg/mL; P<0.05) and also higher levels of progesterone on pregnancy 1 d (4±5 vs. 1±2 ng/mL; P<0.05). However, PL rabbits had lower levels of progesterone on 7 d (6±3 vs. 9±2 ng/mL; P<0.02) and 14 d (8±3 vs. 11±3 ng/mL; P<0.005) than PO does. Our results indicate that the unique endocrine milieu of PL rabbits has a direct bearing on specific behavioral and physiological phenomena that impact productivity on the farm.González-Mariscal, G.; Gallegos, J.; Sierra-Ramírez, A.; Garza Flores, J. (2009). Impact of concurrent pregnancy and lactation on maternal nestbuilding, estradiol and progesterone concentrations in rabbits. World Rabbit Science. 17(3):145-152. doi:10.4995/wrs.2009.65414515217

Impact de pulvérisations de deltaméthrine dans un foyer de leishmaniose de Bolivie

Une unique pulvérisation domiciliaire de K-Othrine à 0,025 g/m2, en début de saison humide, contrôle efficacement les populations domestiques et péridomestiques de #Lutzomyia longipalpis, le vecteur de la leishmaniose viscérale, dans un village submontagnard de la province Nord-Yungas, Bolivie. Ce phlébotome est éliminé des habitations et des poulaillers durant, respectivement, 9 et 10 mois. Par contre, l'impact des traitements sur #Lu. nuneztovari anglesi, le vecteur présumé de la leishmaniose tégumentaire, est beaucoup moins marqué. Il se traduit, plus par une baisse de 50 % du taux de gorgement des populations capturées dans les maisons, que par une diminution de leur densité, difficile à apprécier du fait des variations saisonnières naturelles, et de l'absence de témoin représentatif. Ce résultat n'est pas inattendu, étant donné la forte exophilie de #Lu. n. anglesi$ dans la région. (Résumé d'auteur

Clavo gamma: indicaciones, resultados y complicaciones

El clavo gamma ha sido utilizado como osteosíntesis en el tratamiento de 50 fracturas proximales de fémur, 28 de las cuales fueron consideradas inestables (56%). En cuanto a la consolidación sólo hubo un fracaso con rotura del implante (2%); el resto de los pacientes evolucionaron hacia la curación, precisando 2 de ellos una segunda intervención para dinamizar el foco de fractura mediante la retirada de los tornillos de bloqueo distales. Estos buenos resultados contrastan con las complicaciones surgidas durante la intervención y el postoperatorio inmediato: fisura diafisaria intraoperatoria (8%), fractura diafisaria intraoperatoria (4%), problemas en la colocación de los tornillos de bloqueo distales (6%) y fracturas diafisarias postoperatorias por debajo del clavo (4%). El clavo gamma tiene su indicación en las fracturas proximales inestables de fémur siempre que se realice una técnica quirúrgica rigurosa que minimice los riesgos de complicaciones.The gamma nail has been used as osteosynthesis for the treatment of 50 proximal fractures of femur, 28 of which (56%) were considered unstable. Regarding to consolidation, there was one only failure with breaking of the implant (2%). The remaining patients achieved healing, two of them requiring a second intervention in order to activate the fracture focus through withdrawal of the distal blocking screws. These good results contrast with the complications that appeared during intervention and inmediate postoperatory period: intraoperatory diaphyseal fissure (8%), intraoperatory diaphyseal fracture (4%), problems with setting of distal blocking screws (6%) and postoperatory diaphyseal fractures below the nail (4%). The gamma nail has its indication for proximal unstable fractures of femur, as long as a rigorous surgical technique is practiced, thus minimizing the risks of complications

Maternal behaviour and welfare of the domestic and wild rabbit doe and its litter

El conejo europeo (Oryctolagus cuniculus), además de tener importancia faunística en el Mediterráneo occidental, es una especie ganadera relevante que es la base de un subsector pecuario industrializado orientado a la producción de carne en varios países, sobre todo europeos, mientras que en algunos pa- íses en vías de desarrollo se explota bajo sistemas alternativos orientados a la integración de renta y a la seguridad alimentaria. A la orientación cárnica se suman otras aptitudes productivas heterogéneas que configuran una gran diversidad de sistemas de producción cunícola. Este trabajo revisa el comportamiento materno de la coneja y de su camada, incluyendo su regulación endocrina, tanto en el animal silvestre como en la producción cunícola comercial y alternativa, y se relaciona con los factores de manejo, con la productividad en granja y con el bienestar de la especie. Se analizan también las implicaciones que las normativas sobre bienestar animal comportan respecto al alojamiento, manejo y satisfacción de las necesidades etológicas de las conejas reproductoras y de los gazapos durante la cría, caracterizadas, fundamentalmente, porque en algunos países tienden a proporcionar más espacio y enriquecimiento ambiental en las jaulas.The European rabbit (Oryctolagus cuniculus), in addition to its faunal interest in the western Mediterranean, is a relevant species which in several European countries is the basis of a meat-oriented, industrial livestock subsector, while in many developing countries rabbits are raised under alternative systems aimed at income integration and food security. In addition to meat production, other productive orientations exist that generate a variety of rabbit production systems. This paper reviews the ethology of maternal behaviour of the breeding doe and her litter, including its endocrine regulation, both in wild animal and in industrial and alternative farming systems, and its relation to management factors, productivity and performance as well as the welfare of the species. It also discusses the implications of the regulations concerning animal welfare on housing, management and satisfaction of behavioural needs of breeding does and their litters, which in some countries tend to provide more space and environmental enrichment in cage

Acrometástasis: a propósito de dos casos

Se presentan dos casos de acrometástasis localizados en la falange distal de los dedos de un pie y de una mano. Ambos casos habían sido diagnosticados previamente de lesiones malignas (carcinoma epidermoide de pulmón en el primer caso y carcinoma folicular de tiroides en el otro caso). El tratamiento consistió en la amputación del dedo afectado en ambos pacientes.Two cases of acrometastases in the distal phalanges of the foot and the hand are presented. Both cases were diagnosed previously of malignant lesions (epidermoid carcinoma of lung in the first case and follicular carcinoma of thyroid in the second one). Treatment consisted in amputation of the affected great toe and ring finger in both patients

Diagnostic performance of direct and indirect methods for assessing failure of transfer of passive immunity in dairy calves using latent class analysis

Accurate diagnosis of failure of transfer of passive immunity (FTPI) in newborn calves is an essential component of dairy farm management plan. Several methods (direct and indirect) are available for diagnosis of FTPI in dairy calves. However, the indirect methods offer an advantage over the direct methods in not requiring an experienced veterinarian, rapid, cost efficient and can be performed under field-setting. The objective of this study was to estimate the diagnostic performance of radial immunodiffusion (RID) assay, transmission infrared (TIR) spectroscopy and digital Brix refractometer for diagnosis of FTPI in dairy calves using latent class models at four cut-off values of digital Brix refractometer. Holstein calves (n = 691) from 40 commercial dairy farms in the four Atlantic Canada provinces were blood-sampled and tested for detection of FTPI. Results showed that the number of calves with FTPI was 253 (36.6%) by RID, 194 (28.1%) by TIR and 204 (29.5%) by Brix refractometer at cut-off value of 8.2%. Estimates of SeRID was higher than SeTIR and SeBrix, at all Brix refractometer cut-offs, but with increase of Brix refractometer cut-off from 8.2 to 8.5%, SeRID and SeTIR were decreased from 96.0% (95% PCI: 88.0–99.0) and 79.0% (95% PCI: 70.0–85.0), to 92.0% (95% PCI: 77.0–99.0) and 74.0% (95% PCI: 61.0–82.0), respectively. SpRID and SpTIR were always higher than SpBrix at all tested cut-offs and were above 92.0%, and 96.0%, respectively. With increasing the cut-off of Brix refractometer from 8.2 to 8.5%, SeBrix estimate has remarkably increased from 79.0% (95% PCI: 70.0–96.0) to 95.0% (95% PCI: 87.0–100.0), respectively. Whilst, SpBrix was decreased from 95.0% (95% PCI: 91.0–98.0) at cut-off 8.2% to 84.0% (95% PCI: 78.0–94.0) at cut-off 8.5%. In conclusion, RID has a higher Se than TIR and Brix, if the latter is used with cut-offs of 8.2% or 8.3%. However, the higher the cut-off, the more comparable sensitivities of RID and digital Brix refractometer. The median estimate of SpTIR was always higher than SpRID and SpBrix at all tested cut-offs. However, the 95% confidence interval estimates of the three tests were overlapping across the tested cut-offs of digital Brix refractometer reflecting the inability to prefer a test over the other based on the Sp estimate.info:eu-repo/semantics/acceptedVersio