727 research outputs found
Tomografía computerizada en un caso clínico de hemangiosarcoma cutáneo con patrón de distribución atípico
En los últimos años, la tomografía computerizada está cobrando mayor importancia, llegando a ser uno de los pilares básicos en el diagnóstico por imagen en medicina veterinaria. En el campo de la oncología, aporta mucha información a la hora de hacer un diagnóstico y pronóstico, siendo también de gran utilidad cuando se plantea un tratamiento quirúrgico, facilitando el abordaje, así como en el empleo de radioterapia, donde es muy importante determinar tanto la localización como las dimensiones del tumor. Este caso clínico muestra un patrón atípico de metástasis de un hemangiosarcoma cutáneo primario a nivel inguinal en un perro, con una sintomatología diferente a la esperada en la evolución de esta patología
Hydrological and erosion response at micro-plot to -catchment scale following forest wildfire, north-central Portugal
Wildfires can have important impacts on hydrological and soil erosion processes, due to the destruction of vegetation cover and changes to soil properties. According to Shakesby and Doerr (2006), these wildfire effects are: i) much better known at small spatial scales (especially erosion plots) than at the scale of catchments; ii) much better studied with respect to overland flow and streamflow (and, then, especially peak discharges) than to soil erosion. Following up on a precursor project studying runoff generation and the associated soil losses from micro-plot to slope-scale in Portuguese eucalypt forests, the EROSFIRE-II project addresses the connectivity of these processes across hillslopes as well as within the channel network.
This is done in the Colmeal study area in central Portugal, where the outlet of an entirely burnt catchment of roughly 10 ha was instrumented with a gauging station continuously recording water level and tubidity, and five slopes were each equipped with 4 runoff plots of < 0,5 m2 (“micro-plot”) and 4 slope-scale plots as well as 1 slope-scale sediment fence. Starting one month after the August 2008 wildfire, the plots were monitored at 1- to 2-weekly intervals, depending on the occurrence of rainfall. The gauging station became operational at the end of November 2008, since the in-situ construction of an H-flume required several weeks.
A preliminary analysis of the data collected till the end of 2008, focusing on two slopes with contrasting slope lengths as well as the gauging station: revealed clear differences in runoff and erosion between: (i) the micro-plot and slope-scale plots on the same hillslope; (ii) the two slopes; (iii) an initial dry period and a subsequent much wetter period; (iv) the slopes and the catchment-scale, also depending on the sampling period. These results suggest that the different processes govern the hydrological and erosion response at different spatial scales as well as for different periods, with soil water repellency playing a role during the initial post-fire period.
The current presentation will review these preliminary results based on the data collected during the first year after the wildfire
Producing 'Human Elements Based Medical Technologies' in Biotech Companies: Some Ethical and Organisational Ingredients for Innovative Cooking
This article is based on the findings of an EU-funded qualitative research project, entitled 'From GMP to GBP: Fostering good bioethics practices [GBP] among the European biotechnology industry', which seeks to improve the understanding of bioethical issues through the observation of the daily practices in European biotechnology companies and proposes a methodology approaching ethical issues. The comparative study was carried out in biotech companies in France, Italy, Sweden, Hungary and Belgium which develop a wide range of new technologies, all of them involving human materials or where human subjects participate (in clinical trials). Based on our findings in these local settings, we suggest that the notion of bioethics and the way its production is theorised need to be re-conceptualised. We argue that material practices and moral statements are intermingled in inextricable ways that render the formation of bioethical concerns fully dependent on the organisational landscape in which it is embedded. More precisely, the here presented co-production model of moral statements and organisational practices presents a set of common factors that influence how bioethical discourses are shaped, despite the heterogeneity of their epistemic cultures. For example, the procedural design of cell-based-products, the modes of collecting and storing biological specimen, the relationship between patients and companies and technological transfers to emerging countries are defining components that contribute to the shaping process of bioethical concerns. Thus, the path dependency of bioethical concerns relies on an already existing, specific infrastructure and existing relationships within and outside a company rather than on external judgement subsequently applied to its objects, or a collection of processes of reasoning coming from external institutions
Microemulsions for colorectal cancer treatments: general considerations and formulation of methotrexate
[Abstract] Microemulsions combine the advantages of emulsions with those of nanocarriers, overcoming the stability problems of the former and providing facile scalable systems with compartments adequate for high drug loadings. Recently, microemulsions are gaining attention in the formulation of anticancer drugs not only for topical treatment, but also for systemic delivery as well as for the development of theranostic systems. The aim of this paper is two-fold. First, an updated review about general features, preparation, characterization and pharmaceutical applications, with a special focus on colorectal cancer, is provided. Second, a case study of formulation of methotrexate in microemulsions is presented. Various essential oils (menthol, trans-anethole, α-tocopherol) and surfactants (TPGS-l000, Maxemul 6112, Noigen RN-20) were investigated for the preparation of o/w microemulsions for the delivery of methotrexate, and the ability of methotrexate-loaded microemulsions to inhibit cancer cell growth was then evaluated. Disregarding the surfactants used, menthol and trans-anethole led to cytotoxic microemulsions, whereas α-tocopherol based-formulations induced cell proliferation. These findings highlight the role that the oily component may play in the efficacy and safety of the microemulsions.México. Consejo Nacional de Ciencia y Tecnologia; No. CB-2011/ 168472Ministerio de Economia y Competitividad; SAF2014-52632-RRed Gallega de Investigación sobre Cáncer Colorrectal; R2014/03
Well posedness and smoothing effect of Schrödinger-Poisson equation
In this work we take under consideration the Cauchy problem for the Schrödinger-Poisson type equation i t u=- x2 u+V (u) u-f (∫u∫2) u, where f represents a local nonlinear interaction (we take into account both attractive and repulsive models) and V is taken as a suitable solution of the Poisson equation V=12 ∫x∫ (C- ∫u∫2), C Cc∞ is the doping profile or impurities. We show that this problem is locally well posed in the weighted Sobolev spaces Hs { Hs (R): (1+ x2) 12 ∫∫2 <∞} with s1, which means the local existence, uniqueness, and continuity of the solution with respect to the initial data. Moreover, under suitable assumptions on the local interaction, we show the existence of global solutions. Finally, we establish that for s1 local in time and space, smoothing effects are present in the solution; more precisely, in this problem there is locally a gain of half a derivative. © 2007 American Institute of Physics.Fil:De Leo, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Rial, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Uncoupling protein-1 (UCP1) contributes to the basal proton conductance of brown adipose tissue mitochondria
Proton leak pathways uncouple substrate oxidation from ATP synthesis in mitochondria. These pathways are classified as basal (not regulated) or inducible (activated and inhibited). Previously it was found that over half of the basal proton conductance of muscle mitochondria was catalyzed by the adenine nucleotide translocase (ANT), an abundant mitochondrial anion carrier protein. To determine whether ANT is the unique protein catalyst, or one of many proteins that catalyze basal proton conductance, we measured proton leak kinetics in mitochondria isolated from brown adipose tissue (BAT). BAT can express another mitochondrial anion carrier, UCP1, at concentrations similar to ANT. Basal proton conductance was measured under conditions where UCP1 and ANT were catalytically inactive and was found to be lower in mitochondria from UCP1 knockout mice compared to wild-type. Ablation of another abundant inner membrane protein, nicotinamide nucleotide transhydrogenase, had no effect on proton leak kinetics in mitochondria from liver, kidney or muscle, showing that basal proton conductance is not catalyzed by all membrane proteins. We identify UCP1 as a second protein propagating basal proton leak, lending support to the hypothesis that basal leak pathways are perpetrated by members of the mitochondrial anion carrier family but not by other mitochondrial inner membrane proteins
Communication: Reduced density matrices in molecular systems: Grand-canonical electron states
Grand-canonical like descriptions of many electron atomic and molecular open systems which are characterized by a non-integer number of electrons are presented. Their associated reduced density matrices (RDMs) are obtained by introducing the contracting mapping for this type of distributions. It is shown that there is loss of information when connecting RDMs of different order by partial contractions. The energy convexity property of these systems simplifies the description. Consequently, this formulation opens the possibility to a new look for chemical descriptors such as chemical potential and reactivity among others. Examples are presented to discuss the theoretical aspects of this work. © 2013 AIP Publishing LLC.Fil:Bochicchio, R.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Rial, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Limb-darkened radiation-driven winds from massive stars
We calculated the influence of the limb-darkened finite-disk correction factor in the theory of radiation-driven winds from massive stars. We solved the one-dimensional m-CAK hydrodynamical equation of rotating radiation-driven winds for all three known solutions, i.e., fast, Ω-slow, and δ-slow. We found that for the fast solution, the mass-loss rate is increased by a factor of 10%, while the terminal velocity is reduced about 10%, when compared with the solution using a finite-disk correction factor from a uniformly bright star. For the other two slow solutions, the changes are almost negligible. Although we found that the limb darkening has no effects on the wind-momentum-luminosity relationship, it would affect the calculation of synthetic line profiles and the derivation of accurate wind parameters.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat
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