223 research outputs found
Low-grade fibromyxoid sarcoma of the extremities: A clinicopathologic study of 24cases and review of the literature
Low-grade fibromyxoid sarcoma (LGFMS) and hybrid sclerosing epithelioid fibrosarcoma (SEF)/LGFMS have a low potential for recurrence (10%) and metastasis (5%) but they are notorious for late occurring metastases. The aim of this study was to evaluate the outcome of LGFMS and review similar cases reported in the literature. We retrospectively evaluated 24 LGFMS operated at a single Institution. All cases were histologically revised. Mean age was 34 years (range, 8 to 74). Two cases presented areas of SEF (hybrid tumours). Three patients presented with metastasis at diagnosis. A strong cytoplasmic staining for MUC4 antibody was found in the majority of neoplastic cells. RT-PCR was feasible in 6 cases and it detected the presence of FUS-CREB3L2 fusion gene chimeric transcript. Mean follow-up was 44 months (range, 6 to 217). Two patients developed lung metastasis after 9 and 26 months respectively. Low-grade fibromyxoid sarcoma has a various histopathologic spectrum with few cases of LGFMS that share histopathologic resemblance with SEF, thereby reinforcing a possibility of a link within these two. It is of paramount importance an accurate and extensive sampling and examination of the whole specimen, in order to identify higher risk patients
Simplified HPLC-UV method for the determination of α-tocopherol in plasma
Vitamin E, known for its great nutritional importance, is normally included in animal diets as DL-α-tocopherol acetate.The authors propose a method that makes it possible to determine the concentration of vitamin E in plasma withoutsaponification. This method enable to avoid aggressive treatments on the analyte and complex procedures; it detectsvitamin E only in form of DL-α-tocopherol.Lipoproteins of analysed plasma were denaturised by methanol. Vitamin E was extracted by petroleum ether in presenceof NaCl. The extract was dried by rotavapor at 45 °C, solubilized by methanol and injected in HPLC (C18 column, reversedphase). The quantitative determination was carried out by UV detector settled on 294 nm.Tests of repeatability inter-analysis and intra-analysis gave coefficient of variability (CV%) respectively of 1.64 and2.41%. The mean recovery was 100%
Accurate multiscale simulation of frictional interfaces by Quantum Mechanics/Green's Function molecular dynamics
Understanding frictional phenomena is a fascinating fundamental problem with
huge potential impact on energy saving. Such an understanding requires
monitoring what happens at the sliding buried interface, which is almost
inaccessible by experiments. Simulations represent powerful tools in this
context, yet a methodological step forward is needed to fully capture the
multiscale nature of the frictional phenomena. Here, we present a multiscale
approach based on linked ab initio and Green's function molecular dynamics,
which is above the state-of-the-art techniques used in computational tribology
as it allows for a realistic description of both the interfacial chemistry and
energy dissipation due to bulk phonons in non-equilibrium conditions. By
considering a technologically relevant system composed of two diamond surfaces
with different degrees of passivation, we show that the presented method can be
used not only for monitoring in real-time tribolochemical phenomena such as the
tribologically-induced surface graphitization and passivation effects but also
for estimating realistic friction coefficients. This opens the way to in silico
experiments of tribology to test materials to reduce friction prior to that in
real labs
Multiple or metastatic clear cell chondrosarcoma: a case report
We report multiple synchronous clear-cell chondrosarcomas in a 43-year-old patient. The patient had a lesion in the right proximal humerus and in the left femoral condyle. Bone scintigraphy revealed increased uptake in both foci. Pathological analysis confirmed the diagnosis in both locations. In the proximal humerus, wide resection of the tumour was performed with allograft reconstruction of the joint with osteosynthesis. The femoral condyle was treated with curettage, phenolization, and cementation. Over a follow-up of 10 years no recurrence or metastasis was observed
Application and analysis of interpolation techniques for spatialization of rainfall
Os métodos de interpolação são ferramentas usualmente utilizadas para gerar superfícies distribuídas de uma determinada variável a partir de dados pontuais. Eles contribuem para a compreensão espacial de atributos, sem a necessidade de levantar dados em toda a área de interesse. Assim, avaliaram-se, comparativamente, diferentes métodos de interpolação de chuvas para a bacia hidrográfica do rio Piratinim – noroeste do Rio Grande do Sul, por meio de análise espacial. Dentre os mais variados existentes, selecionaram-se: Inverso de Distância Ponderada (IDW), Método Kriging (KG), Vizinho Natural (NN) e Função de Base Radial Multiquadrada (RBF). Todos os dados pluviométricos foram obtidos no banco de dados do Sistema Nacional de Informações sobre Recursos Hídricos (SNIRH), da Agência Nacional das Águas (ANA). Primeiramente, foi analisada a média anual da série histórica (1990-2010), e, posteriormente, conforme informações disponibilizadas no site do Instituto Nacional de Pesquisas Espaciais (INPE), foram analisados os anos de 1997 (evento El Niño considerado forte) e 2010 (El Niño considerado fraco). O software adotado neste trabalho foi o ArcGIS 10. Realizou-se a validação cruzada dos dados de todos os interpoladores. Os métodos de interpolação empregados para a análise da série histórica e para o ano de 1997 apresentaram valores negativos na correlação. Para o ano de 2010, verificou-se que o NN foi o melhor interpolador, com correlação positiva de 0.7. Assim, conclui-se que a estimativa da precipitação com modelos estatísticos também representa uma alternativa potencial, dada à sua facilidade operacional e capacidade de estimar a precipitação para um local específico, reduzindo o tempo de trabalho e de recursos investidos.The interpolation methods are tools commonly used to generate surfaces distributed in a given variable based on accurate data. They contribute to aid understanding of the spatial attributes without the need to collect data in the entire area of interest. In view of this, this study evaluated comparatively different rainfall interpolation methods for the river basin Piratinim, in the northwest of Rio Grande do Sul, through spatial analysis. Among the variety of existing methods it was selected the following: Inverse Distance Weighted (IDW), Kriging method (KG), Natural Neighbor (NN) and Multi-quadrada Radial Basis Function (RBF). All the rainfall data were obtained from the National Information System on Water Resources (SNIRH) of the National Water Agency (ANA). First, it was analyzed the annual average of the historical series (1990-2010), and later, according to information available in the website of National Institute for Space Research (INPE), it was analyzed the years of 1997 (El Niño event - considered strong) and 2010 (El Niño - considered weak). The software used was the ArcGIS 10 and it was developed the cross-validation of data of all interpolators. The interpolation methods employed for the analysis of the historical series and for the year of 1997 showed negative correlation values. For the year 2010, it was found that the NN was the best interpolator, with positive correlation of 0.7. Thus, it was concluded that the estimated precipitation with statistical models also represents a potential alternative given its operational easiness and capacity to estimate the precipitation for a specific location, reducing labor time and invested resources
Aplicação e análise de técnicas de interpolação para espacialização de chuvasApplication and analysis of interpolation techniques for spatialization of rainfall
Os métodos de interpolação são ferramentas usualmente utilizadas para gerar superfícies distribuídas de uma determinada variável a partir de dados pontuais. Eles contribuem para a compreensão espacial de atributos, sem a necessidade de levantar dados em toda a área de interesse. Assim, avaliaram-se, comparativamente, diferentes métodos de interpolação de chuvas para a bacia hidrográfica do rio Piratinim – noroeste do Rio Grande do Sul, por meio de análise espacial. Dentre os mais variados existentes, selecionaram-se: Inverso de Distância Ponderada (IDW), Método Kriging (KG), Vizinho Natural (NN) e Função de Base Radial Multiquadrada (RBF). Todos os dados pluviométricos foram obtidos no banco de dados do Sistema Nacional de Informações sobre Recursos Hídricos (SNIRH), da Agência Nacional das Águas (ANA). Primeiramente, foi analisada a média anual da série histórica (1990-2010), e, posteriormente, conforme informações disponibilizadas no site do Instituto Nacional de Pesquisas Espaciais (INPE), foram analisados os anos de 1997 (evento El Niño considerado forte) e 2010 (El Niño considerado fraco). O software adotado neste trabalho foi o ArcGIS 10. Realizou-se a validação cruzada dos dados de todos os interpoladores. Os métodos de interpolação empregados para a análise da série histórica e para o ano de 1997 apresentaram valores negativos na correlação. Para o ano de 2010, verificou-se que o NN foi o melhor interpolador, com correlação positiva de 0.7. Assim, conclui-se que a estimativa da precipitação com modelos estatísticos também representa uma alternativa potencial, dada à sua facilidade operacional e capacidade de estimar a precipitação para um local específico, reduzindo o tempo de trabalho e de recursos investidos.Abstract The interpolation methods are tools commonly used to generate surfaces distributed in a given variable based on accurate data. They contribute to aid understanding of the spatial attributes without the need to collect data in the entire area of interest. In view of this, this study evaluated comparatively different rainfall interpolation methods for the river basin Piratinim, in the northwest of Rio Grande do Sul, through spatial analysis. Among the variety of existing methods it was selected the following: Inverse Distance Weighted (IDW), Kriging method (KG), Natural Neighbor (NN) and Multi-quadrada Radial Basis Function (RBF). All the rainfall data were obtained from the National Information System on Water Resources (SNIRH) of the National Water Agency (ANA). First, it was analyzed the annual average of the historical series (1990-2010), and later, according to information available in the website of National Institute for Space Research (INPE), it was analyzed the years of 1997 (El Niño event - considered strong) and 2010 (El Niño - considered weak). The software used was the ArcGIS 10 and it was developed the cross-validation of data of all interpolators. The interpolation methods employed for the analysis of the historical series and for the year of 1997 showed negative correlation values. For the year 2010, it was found that the NN was the best interpolator, with positive correlation of 0.7. Thus, it was concluded that the estimated precipitation with statistical models also represents a potential alternative given its operational easiness and capacity to estimate the precipitation for a specific location, reducing labor time and invested resources
A redução da brecha entre investigação e a prática docente : o livro didático e o movimento CTS
O objetivo do texto é analisar a Coleção Química Cidadã como conjunto que se apoia no movimento CTS em resposta à redução da brecha entre investigação e prática docente. A metodologia é bibliográfica e qualitativa. Os resultados mostram que os três volumes foram elaborados na perspectiva CTS por apresentarem os conteúdos que partem do uso quotidiano, com questões tecnológicas, explorando aspectos sociais, ambientais, políticos e econômicos, tratados a partir das disciplinas de química, biologia, física, geografia e português. As questões científicas da sociedade são abordadas, especialmente as relacionadas ao meio ambiente, com o foco na formação da cidadania. O modo como os livros foram elaborados valoriza o conhecimento prévio do aluno e a história da ciência. De modo geral, a coleção analisada reduz a brecha entre investigação e prática docente
Microstrip Resonators and Broadband Lines for X-band EPR Spectroscopy of Molecular Nanomagnets
We present a practical setup to perform continuous-wave X-band
electron paramagnetic resonance spectroscopy by using planar microstrip lines and
general purpose instrumentation. We fabricated Ag/alumina and Nb/sapphire microstrip
resonators and transmission lines and compared their performance down to
2 K and under applied magnetic field. We used these devices to study single crystals
of molecular Cr3 nanomagnets. By means of X-band planar resonators we measured
angle-dependent spectra at fixed frequency, while broadband transmission lines
were used to measure continuous wave spectra with varying frequency in the range
2–25 GHz. The spectra acquired at low temperatures allowed to extract the essential
parameters of the low-lying energy levels of Cr3 and demonstrate that this method is
particularly suitable to study small crystals of molecular nanomagnets
Primary vascular bone tumors in the spine: a challenge for pathologists and spine oncology surgeons
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