86 research outputs found

    Histological response to radiotherapy is an early event in myxoid liposarcoma

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    Myxoid liposarcoma; Personalized medicine; RadiotherapyLiposarcoma mixoide; Medicina personalizada; RadioterapiaLiposarcoma mixoide; Medicina personalitzada; RadioteràpiaCompared to other sarcomas, myxoid liposarcoma (MLS) is exceptionally sensitive to radiation therapy, but the underlying mechanism remains unknown. The objective was to assess the tissue-based changes in MLS during and after neoadjuvant radiotherapy in 26 patients of the DOREMY trial. Morphological assessment was performed on biopsies pre-treatment, after 8 fractions, 16 factions, and after surgical resection and included percentage of viable tumor cells, hyalinization, necrosis, and fatty maturation. Furthermore, immunohistochemistry was performed for apoptosis (cleaved caspase-3), anti-apoptosis (Bcl-2), activity of mTOR signaling (phospho-S6), hypoxia (CAIX), proliferation (Ki67), inflammation (CD45 and CD68), and microvessel density (CD34 Chalkley count). A pronounced reduction in vital tumor cells was observed early with a drop to 32.5% (median) tumor cells (IQR 10–93.8%) after 8 fractions. This decreased further to 10% (IQR 5–30%) after 16 fractions and 7.5% (IQR 5–15%) in the surgical specimen. All but one patient had an excellent response with < 50% remaining tumor cells. Inversely, treatment response was mainly observed as hyalinization and less often as fatty maturation. Additionally, a decrease of inflammatory cells was noticed especially during the first eight fractions. Microvessel density remained stable over time. Immunohistochemical markers for apoptosis, anti-apoptosis, activity of mTOR signaling, proliferation, and hypoxia did not show any marked changes within the remaining tumor cells during and after radiotherapy. As a modest dose of neoadjuvant radiotherapy induces profound tissue changes in MLS, mainly during the first 8 fractions, current findings might suggest that in a carefully selected patient population further deintensification of radiotherapy might be explored

    Effect of Ageing on the Mechanical Performance of Thermoset Polymers: A Statistical Approach

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    The present work investigates the effect of three different ageing processes (natural, 100% relative humidity and salt spray) on the mechanical performance of two thermoset polymers, epoxy and polyester, commonly used as matrix phase in composite materials. A full factorial design is conducted to evaluate the effect of significant factors and interactions on moisture absorption, tensile and compressive strength and modulus of elasticity of the thermosets. Both polymers reveal a decrease in moisture absorption in the saline environment compared to the completely saturated condition (100% RH). Polyester polymers in harsh environments exhibit higher compressive properties compared to those subjected to natural conditioning. In general, polyester polymers, which are most affected by the positive effect of additional cross-linking, have less moisture absorption and superior mechanical properties compared to epoxy, which is more affected by the negative effect of plasticization

    The Effect of Aluminium Surface Treatments on the Bonding Properties of Silica-Modified Epoxy Adhesive Joints: A Statistical Approach

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    A full factorial design is carried out to investigate the effects of different surface treatments, the inclusion of silica microparticles and the use of wash primer on the apparent shear strength and adherent strength of single-lap aluminium joints. Scanning electron microscopy, surface energy and roughness measurements are performed to characterise the aluminium surface. The results show that the use of wash primer decreases the apparent shear strength of the joints significantly. The cohesive failure of the primer is the main cause of the reduction in strength. On the other hand, the inclusion of 10 wt.% of silica microparticles in the adhesive layers increases the shear strength by 26%. Surfaces treated with NaOH for one minute, without using a wash primer, result in the most resistant joint. In contrast to the apparent shear strength, adherent strength is most effective when only degreasing is considered

    Pré-filtration in boulder and slow sand filtration with non-woven synthetic layers and granulated vegetal coal to improve quality in wastewater treated by constructed wetlands

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    The objective of this study was the comparison between two filtration systems, being one composed of a boulder pre-filter followed by a slow filter with sand as filtration media and a non-woven synthetic fabric in the upper part, and the other one composed of a boulder pre-filter followed by a slow filter with sand as filtration media and granular activated charcoal and a non-woven synthetic fabric in the upper part, for the purification of household effluents treated in cultivated beds, to be applied in fertigation. The filtration systems were compared to assess the efficiency in the removal of the parameters: suspended solids, turbidity, apparent color, chemical oxygen demand, dissolved oxygen, iron, manganese, total coliforms and E. coli. The two systems operated 24 hours a day, with the same application rate, treating a total final flow of 1.5 m³ day-1, while the application rate for the pre-filtration unit was 8.4 m³ m-2 day-1 on average and for each of the slow filtration units it was 2.7 m³ m-2 day-1 on average. The pre-filtration and slow filtration units were efficient in the reduction of suspended solids concentrations, turbidity, apparent color and COD, for the purification of previously treated domestic sewage. The use of granular activated charcoal combined with sand in the slow filter allowed a higher efficiency in the removal of suspended solids, color, turbidity, total coliforms and E. Coli., without increasing the initial head loss. The use of effluents is possible in the fertigation practice, where the disinfection process may be necessary or not, depending on the cultivation and the irrigation system adopted.O presente trabalho teve como objetivo comparar sistemas de filtragem, composto de pré-filtro de pedregulho seguido de filtro lento com o meio filtrante areia e no topo manta sintética não tecida e pré-filtro de pedregulho seguido de filtro lento com meio filtrante areia e carvão ativado granular e no topo manta sintética não tecida, para polimento de efluentes domésticos tratados em leitos cultivados, visando à aplicação na fertirrigação. Na comparação dos sistemas de filtragem, avaliou-se a eficiência de remoção dos parâmetros: sólidos em suspensão, turbidez, cor aparente, demanda química de oxigênio, oxigênio dissolvido, ferro, manganês, coliformes totais e E. coli. Os dois sistemas operavam 24 horas por dia, com a mesma taxa de aplicação, tratando uma vazão total final de 1,5 m³ dia-1, sendo que a taxa de aplicação para a unidade de pré-filtração era, em média, de 8,4 m³ m-2 dia-1 e para cada uma das unidades de filtração lenta era, em media, de 2,7 m³ m-2 dia-1. As unidades de pré-filtração e filtração lenta mostraram-se eficientes na redução das concentrações de sólidos suspensos, turbidez, cor aparente e DQO, como polimento de esgotos domésticos previamente tratados. O uso de carvão ativado granular, em combinação com areia, proporcionou ao filtro lento maior eficiência na remoção de sólidos suspensos, cor, turbidez, coliformes totais e E. Coli., sem com isso aumentar a perda de carga inicial. Existe a possibilidade de utilização dos efluentes para a prática da fertirrigação, sendo necessário o processo de desinfecção ou não, dependendo da cultura e o sistema de irrigação utilizado.80381

    Polymorphism analysis of the CTLA-4 gene in paracoccidioidomycosis patients

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    The CTLA-4 protein is expressed in activated T cells and plays an essential role in the immune response through its regulatory effect on T cell activation. Polymorphisms of the CTLA-4 gene have been correlated with autoimmune, neoplastic and infectious illnesses. This work aimed to verify possible associations between single nucleotide polymorphisms (SNPs) in CTLA-4, -318C/T in the promoter and +49A/G in exon 1 and paracoccidioidomycosis (PCM) caused by Paracoccidioides brasiliensis. For this purpose, 66 chronic form PCM patients and 76 healthy controls had their allele, genotype and haplotype frequencies determined. The genetic admixture structure of the patients and controls was evaluated to eliminate ancestral bias. The comparison of frequencies indicated no significant differences between patients and controls that could link the SNPs to PCM. Groups were admixture matched with no difference observed in population ancestry inference, indicating that the absence of association between CTLA-4 polymorphisms and PCM could not be attributed to ancestral bias. This study showed that there was no association between the CTLA-4 SNPs -318 and +49 and the resistance or susceptibility to PCM.22022

    Desenvolvimento de metodologia para o isolamento de bactérias metanotróficas oriundas de solos florestais.

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    O metano (CH4) é considerado um dos gases de efeito estufa (GEE) responsáveis pelo aquecimento global. Mitigar suas emissões é primordial para reduzir o impacto do aumento de temperatura mundial. Uma alternativa para isto seria criar tecnologias para aumentar o consumo de metano via a utilização de bactérias metanotróficas, que oxidam o CH4 reduzindo sua concentração na atmosfera. Todavia, esse grupo microbiano apresenta algumas limitações no cultivo que exige tempo e muitas repicagens para se obter o isolado puro, impossibilitando avanços tecnológicos no sentido de contribuir para mitigação do CH4. Este estudo objetivou testar duas técnicas para o isolamento das bactérias metanotróficas em solos florestais: por diluição até a extinção e por plaqueamento direto. A primeira técnica mostrou-se trabalhosa e demorada, entretanto o crescimento das bactérias em meio dNMS enriquecido com metano em dessecador foi positivo. A segunda técnica foi prática e rápida, o teste colorimétrico revela de maneira eficiente os metanotróficos para purificação, agilizando o processo inicialmente. A caracterização de bactérias eficientes em solos requer a otimização dos métodos de isolamento testados o que requer a continuidade dos estudos.http://rpcs2019.com.br/2019_Anais_da_VI_RPCS.pdf Em 14/10/1
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