410 research outputs found
Clinical presentation and treatment of multifocal epitrichial sweat gland carcinoma in a horse
Epitrichial gland carcinoma is a very rare type of skin tumour in horses. This report describes a horse presenting multiple nodules with associated normal, alopecic and ulcerated skin diagnosed via histopathology as epitrichial gland carcinoma. Treatment consisted of combined surgical excision, topical therapy for ulcerated nodules and cryotherapy for non-ulcerated tumours. Six months following therapy, the excised masses had not regrown and only 10 out of 25 small tumours previously treated with cryotherapy were noticeable
Low X-Ray Luminosity Galaxy Clusters: Main goals, sample selection, photometric and spectroscopic observations
We present the study of nineteen low X-ray luminosity galaxy clusters (L 0.5--45 erg s), selected from the ROSAT
Position Sensitive Proportional Counters (PSPC) Pointed Observations (Vikhlinin
et al. 1998) and the revised version of Mullis et al. (2003) in the redshift
range of 0.16 to 0.7. This is the introductory paper of a series presenting the
sample selection, photometric and spectroscopic observations and data
reduction. Photometric data in different passbands were taken for eight galaxy
clusters at Las Campanas Observatory; three clusters at Cerro Tololo
Interamerican Observatory; and eight clusters at the Gemini Observatory.
Spectroscopic data were collected for only four galaxy clusters using Gemini
telescopes. With the photometry, the galaxies were defined based on the
star-galaxy separation taking into account photometric parameters. For each
galaxy cluster, the catalogues contain the PSF and aperture magnitudes of
galaxies within the 90\% completeness limit. They are used together with
structural parameters to study the galaxy morphology and to estimate
photometric redshifts. With the spectroscopy, the derived galaxy velocity
dispersion of our clusters ranged from 507 km~s for [VMF98]022 to 775
km~s for [VMF98]097 with signs of substructure. Cluster membership has
been extensively discussed taking into account spectroscopic and photometric
redshift estimates. In this sense, members are the galaxies within a projected
radius of 0.75 Mpc from the X-ray mission peak and with cluster centric
velocities smaller than the cluster velocity dispersion or 6000 km~s,
respectively. These results will be used in forthcoming papers to study, among
the main topics, the red cluster sequence, blue cloud and green populations;
the galaxy luminosity function and cluster dynamics.Comment: 13 pages, 6 tables, 9 figures. Uses emulateapj. Accepted for
publication in The Astronomical Journal. Some formatting errors fixe
Highly dispersed copper oxide on silica: Towards an efficient catalyst for continuous glycerol dehydration to acetol
[EN] In most current processes aimed at producing biodiesel glycerol is still a co-product, and its valorisation is essential for the biorefinery. This work relies on previous results showing the dependence of the selective dehydration of glycerol to acetol (hydroxyacetone) on achieving a moderate acidity and the redox functionality of copper to complete the chemical process. In this sense, this reaction was studied using CuO supported on silica. Different silicas and copper incorporation methodologies were investigated to develop the best CuO/SiO2 material. Interestingly, these CuO-based materials developed acidity and became more active when increasing the copper oxide dispersion, thereby going from poorly to intensely effective to dehydrate glycerol selectively to acetol. Catalysts were characterised by different techniques (i.e., ICP, N2 adsorption, XRD, TPR, HR-TEM, etc.) to explain the differences observed in catalytic activity and acetol yield based on their physicochemical properties.Financial support by Spanish Government (CTQ-2015-67592, PGC2018-097277-B-I00 and SEV-2016-0683) is gratefully acknowl-edged. J.M. thanks Spanish Government (CTQ-2015-67592) for the Ph.D. fellowship. Authors also thank Miriam Parreno Romero and the Electron Microscopy Service of Universitat Polite`cnica de València for their support.Mazarío-Santa-Pau, J.; Cecilia, JA.; Rodríguez-Castellón, E.; Domine, ME. (2023). Highly dispersed copper oxide on silica: Towards an efficient catalyst for continuous glycerol dehydration to acetol. Applied Catalysis A General. 652. https://doi.org/10.1016/j.apcata.2023.11902965
Historical Review and Update of Surgical Treatment for Corneal Endothelial Diseases
The cornea remains in a state of deturgescence, maintained by endothelial cell Na+/K+ ATPase and by tight junctions between endothelial cells that limit entrance of fluid into the stroma. Fuchs' endothelial corneal dystrophy (FECD) was initially described by Fuchs in 1910 as a combination of epithelial and stromal edema in older patients. It manifests as bilateral, albeit asymmetric, central corneal guttae, corneal edema, and reduced vision. When edema is severe, the corneal epithelium can detach from its basement membrane, creating painful bullae on the anterior surface of the cornea. The course of this dystrophy can be further accelerated after intraocular surgery, specifically cataract extraction. Pseudophakic bullous keratopathy (PBK) is endothelial cell loss caused by surgery in the anterior chamber. If the corneal endothelium is damaged during surgery, the same spectrum of symptoms as found in FECD can develop. In the nineteenth century, penetrating keratoplasty was the only surgical procedure available for isolated endothelial disease. In the 1960s, Dr. José Barraquer described a method of endothelial keratoplasty using an anterior approach via laser-assisted in situ keratomileusis (LASIK) flap. In 1999, Melles and colleague described their technique of posterior lamellar keratoplasty. Later, Melles et al. started to change host dissection using simple "descemetorhexis" in a procedure known as Descemet's stripping endothelial keratoplasty. Following the widespread adoption of Descemet's stripping automated endothelial keratoplasty, the Melles group revisited selective Descemet's membrane transplantation and reported the results of a new procedure, Descemet's membrane endothelial keratoplasty (DMEK). Recently, some eye banks have experimented with the preparation of DMEK/Descemet's membrane automated endothelial keratoplasty donor tissue that may help the surgeon avoid the risk of tissue loss during the stromal separation step. Recently, the authors described a new bimanual technique for insertion and positioning of endothelium-Descemet membrane grafts in DMEK
Technological and infrastructure collaborative seismic research in Western Mexico
In February and March 2014, Spanish, Mexican and British scientists
and technicians explored the western margin of Mexico, a region with a high occurrence
of large earthquakes (> Mw = 7.5) and tsunami generation, on board the
British Royal Research Ship James Cook. This successful joint cruise, named TSUJAL,
was made possible thanks to a cooperative agreement between NERC and CSIC as
part of the Ocean Facilities Exchange Group (OFEG), a major forum of European
oceanographic institutions for the exchange of ship time, equipment and personnel.
A dense geophysical data set was acquired using for the first time 6 km length
seismic streamer facilities from Spain’s Consejo Superior de Investigaciones Cientificas
(CSIC), usually operating in the Spanish RV Sarmiento de Gamboa, onboard
the British RRS James Cook by solving all mechanical, electrical and electronic
problems. The RRS James Cook in turn provides the seismic source and the acoustic,
hullmounted echosounder operated by the British Natural Environment Research
Council (NERC). Multiscale seismic and echosounder images unravel the subduction
geometry, nature of the crust, and evidence faults and mass wasting processes. The
data are crucial to estimating fault seismic parameters, and these parameters are
critical to carrying out seismic hazard in Mexico, especially when considering largemagnitude
earthquakes (Mw 8.0), and to constrain tsunami models.Peer Reviewe
Preparation and characterisation of calcined Mg/Al hydrotalcites impregnated with alkaline nitrate and their activities in the combustion of particulate matter
The effect of incorporating alkaline nitrates in hydrotalcites for use in the combustion of particulate matter from diesel emissions has been studied. The catalysts were characterised by X-ray diffraction (XRD), N2 adsorption, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), elemental analysis (EA), atomic absorption spectrophotometry (AAS) temperature programmed reduction (TPR) and Fourier transform infrared spectroscopy (FTIR). Activity measurements were carried out using a thermobalance in air and using a fixed-bed reactor with a NO/O2 flow. The observed activities decreased in the following order: HTMgAlcCs>HTMgAlcK>HTMgAlcLi>HTMgAlc.Centro de Investigación y Desarrollo en Ciencias Aplicada
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Mixed Ionic-Electronic Conductivity, Redox Behavior and Thermochemical Expansion of Mn-Substituted 5YSZ as an Interlayer Material for Reversible Solid Oxide Cells
Manganese-substituted 5 mol.% yttria-stabilized zirconia (5YSZ) was explored as a prospective material for protective interlayers between electrolyte and oxygen electrodes in reversible solid oxide fuel/electrolysis cells. [(ZrO2)0.95(Y2O3)0.05]1−x[MnOy]x (x = 0.05, 0.10 and 0.15) ceramics with cubic fluorite structure were sintered in air at 1600 °C. The characterization included X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), thermogravimetry and dilatometry in controlled atmospheres, electrical conductivity measurements, and determination of oxygen-ion transference numbers by the electromotive force (EMF) technique. Mn-substituted 5YSZ solid solutions exhibit variable oxygen nonstoichiometry with manganese cations in a mixed 2+/3+ oxidation state under oxidizing conditions. Substitution by manganese gradually increases the extent of oxygen content variation on thermal/redox cycling, chemical contribution to thermal expansion and dimensional changes on reduction. It also deteriorates oxygen-ionic conductivity and improves p-type electronic conductivity under oxidizing conditions, leading to a gradual transformation from predominantly ionic to prevailing electronic transport with increasing x. Mn2+/3+→Mn2+ transformation under reducing atmospheres is accompanied by the suppression of electronic transport and an increase in ionic conductivity. All Mn-substituted 5YSZ ceramics are solid electrolytes under reducing conditions. Prolonged treatments in reducing atmospheres, however, promote microstructural changes at the surface of bulk ceramics and Mn exsolution. Mn-substituted 5YSZ with 0.05 ≤ x < 0.10 is considered the most suitable for the interlayer application, due to the best combination of relevant factors, including oxygen content variations, levels of ionic/electronic conductivity and thermochemical expansion
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