88 research outputs found
Lipoblastoma retroperitoneal en un lactante. Caso clínico
ResumenIntroducciónEl lipoblastoma es una neoplasia benigna del tejido adiposo, de presentación infrecuente y casi exclusiva en niños menores de 3 años. Usualmente se presenta en las extremidades como una masa indolora de crecimiento progresivo, estableciéndose su diagnóstico definitivo mediante análisis histológico y citogenético.ObjetivoPresentar un caso clínico de lipoblastoma de ubicación inhabitual en una lactante y revisar la literatura al respecto.Caso clínicoLactante mayor de 16 meses, con aumento de volumen abdominal de 6 meses de evolución, asociado a una ingesta alimentaria disminuida, sin otros síntomas. El estudio de imagen reveló una imagen de aspecto lipoideo que comprometía casi la totalidad de la cavidad abdominal, muy sugerente de lipoblastoma, realizándose la resección de un tumor retroperitoneal de 18cm de diámetro que rechazaba los órganos vecinos. El análisis histológico fue suficiente para confirmar el diagnóstico. En el seguimiento no hubo recidiva.ConclusiónTomando en cuenta la baja frecuencia de esta afección y su inusual presentación, se reporta el caso de esta paciente, para considerarlo dentro del diagnóstico diferencial de masa abdominal en un lactante.AbstractIntroductionLipoblastoma is a benign neoplasia of the adipose tissue. It is a rare conditionand almost exclusively presents in children under 3 years old. It usually occurs in extremities as a painless volume increase of progressive growth, with the definitive diagnosis being established by pathological and cytogenetic analysis. The treatment of choice is complete resection, and follow-up period of up to five years is recommended due to a recurrence of up to 25%.ObjectiveTo present an unusual location of this uncommon condition in an infant, and review the related literature.Case reportA sixteen-month child with an increase in abdominal growth of six-months progression, associated with a decreased food intake, and with no other symptoms. The imaging study revealed a lipoid-like image compromising almost the entire abdominal cavity, very suggestive of lipoblastoma. A resection was performed on an 18cm diameter retroperitoneal tumour that rejected the adjacent organs. Histological analysis was enough to confirm diagnosis without the need for cytogenetic analysis. The follow-up showed no recurrence of the disease.ConclusionGiven the rarity of this disease and its unusual presentation, we communicate this clinical case, in order to be considered in the differential diagnosis of abdominal mass in chilhood
Crater formation in gold nanoislands due to mev self-ion irradiation
The modification of gold nanoislands, grown on silicon substrates under high-vacuum conditions, by MeV self-ion irradiation has been studied by using scanning electron microscopy, transmission electron microscopy, atomic force microscopy, and x-ray reflectivity. Upon irradiation with 1.5MeVAu2+, two types of craters are observed on the Au islands: Empty craters and craters with a central hillock. The contribution of plastic flow, pressure spike, and sputtering to the crater formation during the ion impacts on the gold islands is analyzed. Thermal spike confinement within the gold islands is also proposed to be one of the possible reasons for crater formation in nanoislands
Recommended from our members
Bright spots: seeds of a good Anthropocene
The scale, rate, and intensity of humans’ environmental impact has engendered broad discussion about how to find plausible pathways of development that hold the most promise for fostering a better future in the Anthropocene. However, the dominance of dystopian visions of irreversible environmental degradation and societal collapse, along with overly optimistic utopias and business‐as‐usual scenarios that lack insight and innovation, frustrate progress. Here, we present a novel approach to thinking about the future that builds on experiences drawn from a diversity of practices, worldviews, values, and regions that could accelerate the adoption of pathways to transformative change (change that goes beyond incremental improvements). Using an analysis of 100 initiatives, or “seeds of a good Anthropocene”, we find that emphasizing hopeful elements of existing practice offers the opportunity to: (1) understand the values and features that constitute a good Anthropocene, (2) determine the processes that lead to the emergence and growth of initiatives that fundamentally change human–environmental relationships, and (3) generate creative, bottom‐up scenarios that feature well‐articulated pathways toward a more positive future
Spatio-Temporal Characteristics of Global Warming in the Tibetan Plateau during the Last 50 Years Based on a Generalised Temperature Zone - Elevation Model
Temperature is one of the primary factors influencing the climate and ecosystem, and examining its change and fluctuation could elucidate the formation of novel climate patterns and trends. In this study, we constructed a generalised temperature zone elevation model (GTEM) to assess the trends of climate change and temporal-spatial differences in the Tibetan Plateau (TP) using the annual and monthly mean temperatures from 1961-2010 at 144 meteorological stations in and near the TP. The results showed the following: (1) The TP has undergone robust warming over the study period, and the warming rate was 0.318°C/decade. The warming has accelerated during recent decades, especially in the last 20 years, and the warming has been most significant in the winter months, followed by the spring, autumn and summer seasons. (2) Spatially, the zones that became significantly smaller were the temperature zones of -6°C and -4°C, and these have decreased 499.44 and 454.26 thousand sq km from 1961 to 2010 at average rates of 25.1% and 11.7%, respectively, over every 5-year interval. These quickly shrinking zones were located in the northwestern and central TP. (3) The elevation dependency of climate warming existed in the TP during 1961-2010, but this tendency has gradually been weakening due to more rapid warming at lower elevations than in the middle and upper elevations of the TP during 1991-2010. The higher regions and some low altitude valleys of the TP were the most significantly warming regions under the same categorizing criteria. Experimental evidence shows that the GTEM is an effective method to analyse climate changes in high altitude mountainous regions
Development of a new generation of optical slope measuring profiler
A collaboration, including all DOE synchrotron labs, industrial vendors of x-ray optics, and with active participation of the HBZ-BESSY-II optics group has been established to work together on a new slope measuring profiler -- the optical slope measuring system (OSMS). The slope measurement accuracy of the instrument is expected to be<50 nrad for the current and future metrology of x-ray optics for the next generation of light sources. The goals were to solidify a design that meets the needs of mirror specifications and also be affordable; and to create a common specification for fabrication of a multi-functional translation/scanning (MFTS) system for the OSMS. This was accomplished by two collaborative meetings at the ALS (March 26, 2010) and at the APS (May 6, 2010)
Recommended from our members
Spatial and species-level predictions of road mortality risk using trait data
Aim: Wildlife-vehicle collisions are recognized as one of the major causes of mortality for many species. Empirical estimates of road mortality show that some species are more likely to be killed than others but to what extend this variation can be explained and predicted using intrinsic species characteristics remains poorly understood. This study aims to identify general macroecological patterns associated to road mortality and generate spatial and species-level predictions of risks.
Location: Brazil
Time period: 2001-2014
Major taxa: Birds and mammals
Methods: We fitted trait-based random forest regression models (controlling for survey characteristics) to explain 783 empirical road mortality rates from Brazil, representing 170 bird and 73 mammalian species. Fitted models were then used to make spatial and species-level prediction of road mortality risk in Brazil considering 1775 birds and 623 mammals which occur within the country’s continental boundaries.
Results: Survey frequency and geographic location were key predictors of observed rates, but mortality was also explained by species’ body size, reproductive speed and ecological specialization. Spatial predictions revealed high potential standardized (per km road) mortality risk in Amazonia for birds and mammals, and additionally high risk in Southern Brazil for mammals. Given the existing road network, these predictions mean more than 8 million birds and 2 million mammals could be killed per year in Brazilian roads. Furthermore, predicted rates for all Brazilian endotherm uncovered potential vulnerability to road mortality of several understudied species which are currently listed as threatened by the IUCN.
Conclusion: With a fast-expanding global road network, there is an urgent need to develop improved approaches to assess and predict road-related impacts. This study illustrates the potential of trait-based models as assessment tools to better understand correlates of vulnerability to road mortality across species, and as predictive tools for difficult to sample or understudied species and areas
Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications
Superparamagnetic iron oxide nanoparticles
can providemultiple benefits for biomedical applications
in aqueous environments such asmagnetic separation or
magnetic resonance imaging. To increase the colloidal
stability and allow subsequent reactions, the introduction
of hydrophilic functional groups onto the particles’
surface is essential. During this process, the original
coating is exchanged by preferably covalently bonded
ligands such as trialkoxysilanes. The duration of the
silane exchange reaction, which commonly takes more
than 24 h, is an important drawback for this approach. In
this paper, we present a novel method, which introduces
ultrasonication as an energy source to dramatically
accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove
the generic character, different functional groups were
introduced on the surface including polyethylene glycol
chains, carboxylic acid, amine, and thiol groups. Their
colloidal stability in various aqueous buffer solutions as
well as human plasma and serum was investigated to
allow implementation in biomedical and sensing
applications.status: publishe
Using Agent-Based Modelling to Inform Policy – What Could Possibly Go Wrong?
© 2019, Springer Nature Switzerland AG. Scientific modelling can make things worse, as in the case of the North Atlantic Cod Fisheries Collapse. Some of these failures have been attributed to the simplicity of the models used compared to what they are trying to model. MultiAgent-Based Simulation (MABS) pushes the boundaries of what can be simulated, prompting many to assume that it can usefully inform policy, even in the face of complexity. That said, MABS also brings with it new difficulties and potential confusions. This paper surveys some of the pitfalls that can arise when MABS analysts try to do this. Researchers who claim (or imply) that MABS can reliably predict are criticised in particular. However, an alternative is suggested – that of using MABS for a kind of uncertainty analysis – identifying some of the possible ways a policy can go wrong (or indeed go right). A fisheries example is given. This alternative may widen, rather than narrow, the range of evidence and possibilities that are considered, which could enrich the policy-making process. We call this Reflexive Possibilistic Modelling
- …