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

“Estudio de las resistencias a Aminoglicósidos en enterobacterias de origen hospitalario”

The aminoglycoside antibiotics modifying enzymes and their genetic properties from 97 entero bacteria strains resistant to several aminoglycoside antibiotics isolated at the Universitary Hospital of Granada were studied. These enzymes were detected in 82 strains (84,5 %) and their genetics determinants were localized in 74 strains (90,2 %) on conjugative plasmids. 8 strains (9,8 %) had their genetics determinant on plasmid transferred only by transformation. Four types of enzymes were found, APH(3'), AAC(3), AAC(6') and ANT(2") in this strains. Our results show a situation of endemic resistance towards those antibiotics without control in this hospital.Se estudia la presencia de enzimas modificantes de antibióticos aminoglicósidos y su origen genético en 97 cepas de enterobacterias resistentes a diversos aminoglicósidos y aisladas en el Hospital Universitario de Granada. La presencia de tales enzimas se detectó en 82 cepas (84,50/0) cuyos determinantes génicos se localizaron en 74 casos (90,2 %) sobre plásmidos conjugativos, y en 8 (9,8 %) en plásmidos que únicamente se pudieron transferir mediante transformación. Se identificaron 4 tipos de enzimas, APH(3'), AAC(3), AAC(6') Y ANT(2") respectivamente según su frecuencia de aparición. Los resultados obtenidos indican la existencia de un estado de resistencia endémica, acentuado en el caso de aquellos antibióticos cuyo uso prácticamente no se controla, y aportan la base de conocimientos necesaria para la determinación de la evolución de las mismas en nuestro hospital con fines epidemiológicos

Estudio de las resistencias a Aminoglicósidos en enterobacterias de origen hospitalario

Se estudia la presencia de enzimas modificantes de antibióticos aminoglicósidos y su origen genético en 97 cepas de enterobacterias resistentes a diversos aminoglicósidos y aisladas en el Hospital Universitario de Granada. La presencia de tales enzimas se detectó en 82 cepas (84,50/0) cuyos determinantes génicos se localizaron en 74 casos (90,2 %) sobre plásmidos conjugativos, y en 8 (9,8 %) en plásmidos que únicamente se pudieron transferir mediante transformación. Se identificaron 4 tipos de enzimas, APH(3'), AAC(3), AAC(6') Y ANT(2") respectivamente según su frecuencia de aparición. Los resultados obtenidos indican la existencia de un estado de resistencia endémica, acentuado en el caso de aquellos antibióticos cuyo uso prácticamente no se controla, y aportan la base de conocimientos necesaria para la determinación de la evolución de las mismas en nuestro hospital con fines epidemiológicos.The aminoglycoside antibiotics modifying enzymes and their genetic properties from 97 entero bacteria strains resistant to several aminoglycoside antibiotics isolated at the Universitary Hospital of Granada were studied. These enzymes were detected in 82 strains (84,5 %) and their genetics determinants were localized in 74 strains (90,2 %) on conjugative plasmids. 8 strains (9,8 %) had their genetics determinant on plasmid transferred only by transformation. Four types of enzymes were found, APH(3'), AAC(3), AAC(6') and ANT(2") in this strains. Our results show a situation of endemic resistance towards those antibiotics without control in this hospital

Crossed-beam energy transfer : Polarization effects and evidence of saturation

Recent results on crossed-beam energy transfer are presented. Wavelength tuning was used to vary the amount of energy transfer between two beams in a quasi-stationary plasma with carefully controlled conditions. The amount of transfer agreed well with calculations assuming linear ion acoustic waves (IAWs) with amplitudes up to . Increasing the initial probe intensity to access larger IAW amplitudes for otherwise fixed conditions yields evidence of saturation. The ability to manipulate a beam's polarization, which results from the anisotropic nature of the interaction, is revisited; an example is provided to demonstrate how polarization effects in a multibeam situation can dramatically enhance the expected amount of energy transfer

Laser generated neutron source for neutron resonance spectroscopy

Copyright 2010 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 17(10), 100701, 2010 and may be found at http://dx.doi.org/10.1063/1.348421

Translational web robots for pathogen genome analysis

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Updated African biomass burning emission inventories in the framework of the AMMA-IDAF program, with an evaluation of combustion aerosols

African biomass burning emission inventories for gaseous and particulate species have been constructed at a resolution of 1 km by 1km with daily coverage for the 2000–2007 period. These inventories are higher than the GFED2 inventories, which are currently widely in use. Evaluation specifically focusing on combustion aerosol has been carried out with the ORISAM-TM4 global chemistry transport model which includes a detailed aerosol module. This paper compares modeled results with measurements of surface BC concentrations and scattering coefficients from the AMMA Enhanced Observations period, aerosol optical depths and single scattering albedo from AERONET sunphotometers, LIDAR vertical distributions of extinction coefficients as well as satellite data. Aerosol seasonal and interannual evolutions over the 2004–2007 period observed at regional scale and more specifically at the Djougou (Benin) and Banizoumbou (Niger) AMMA/IDAF sites are well reproduced by our global model, indicating that our biomass burning emission inventory appears reasonable

Search for transient optical counterparts to high-energy IceCube neutrinos with Pan-STARRS1

In order to identify the sources of the observed diffuse high-energy neutrino flux, it is crucial to discover their electromagnetic counterparts. IceCube began releasing alerts for single high-energy ($E > 60$ TeV) neutrino detections with sky localisation regions of order 1 deg radius in 2016. We used Pan-STARRS1 to follow-up five of these alerts during 2016-2017 to search for any optical transients that may be related to the neutrinos. Typically 10-20 faint ($m < 22.5$ mag) extragalactic transients are found within the Pan-STARRS1 footprints and are generally consistent with being unrelated field supernovae (SNe) and AGN. We looked for unusual properties of the detected transients, such as temporal coincidence of explosion epoch with the IceCube timestamp. We found only one transient that had properties worthy of a specific follow-up. In the Pan-STARRS1 imaging for IceCube-160427A (probability to be of astrophysical origin of $\sim$50 %), we found a SN PS16cgx, located at 10.0' from the nominal IceCube direction. Spectroscopic observations of PS16cgx showed that it was an H-poor SN at z = 0.2895. The spectra and light curve resemble some high-energy Type Ic SNe, raising the possibility of a jet driven SN with an explosion epoch temporally coincident with the neutrino detection. However, distinguishing Type Ia and Type Ic SNe at this redshift is notoriously difficult. Based on all available data we conclude that the transient is more likely to be a Type Ia with relatively weak SiII absorption and a fairly normal rest-frame r-band light curve. If, as predicted, there is no high-energy neutrino emission from Type Ia SNe, then PS16cgx must be a random coincidence, and unrelated to the IceCube-160427A. We find no other plausible optical transient for any of the five IceCube events observed down to a 5$\sigma$ limiting magnitude of $m \sim 22$ mag, between 1 day and 25 days after detection.Comment: 20 pages, 6 figures, accepted to A&