Análise comparativa de resultados de espetrometria gama portátil em afloramentos rochosos

São comparadas estimativas de elementos obtidas por espetrometria gama portátil em afloramentos de rochas metamórficas e ígneas, assim como medições de campo e análises laboratoriais para uma das rochas ígneas consideradas, tendo em vista contribuir para a discussão da utilidade da espetrometria portátil técnica na avaliação dos ma teriaisEste trabalho foi desenvolvido no âmbito das atividades do Lab2PT- Laboratório de Paisagens, Património e Território (AUR/04509) financiado pela FCT através de fundos nacionais e quando aplicável do cofinanciamento do FEDER, no âmbito dos novos acordos de parceria PT2020 e COMPETE 2020 – POCI-01-0145-FEDER-007528.info:eu-repo/semantics/publishedVersio

Additive manufacturing of NiTi-Ti6Al4V multi-material cellular structures targeting orthopedic implants

The amount of hip revision surgeries is significantly increasing due to the loss of fixation between implant and bone, that leads to implant failure. The stiffness mismatch between Ti6Al4V hip implants and bone tissue, the non-uniform implant-bone contact pressure, and the poor wear resistance of Ti6Al4V are pointed as three critical issues that contribute to these implant's failure. In this study, a multi-material design and fabrication concept was exploited aiming to change traditional manufacturing paradigms, by allocating different biomaterials in a single component targeting a multi-functional hip implant. Selective Laser Melting technology was explored to fabricate NiTi-Ti6Al4V multi-material cellular structures with a Ti6Al4V inner region and a NiTi outer region. This work was focused on the SLM fabrication and processing parameters validation on a commercial SLM equipment. The morphological analyses allowed to assess a successful solidification and bond between NiTi and Ti6Al4V materials in the transition region. The shear tests revealed a high bond strength of the transition region with an average strength of 33 MPa. The nano-indentation results showed that the Ti6Al4V region exhibits a higher hardness and elastic modulus when compared with the NiTi region. This work is a part of a broader objective that aims to create a NiTi-Ti6Al4V multi-material and cellular structured hip implant capable to provide customized stiffness, superior wear resistance and a controlled NiTi outer region volume change.This work was supported by FCT (Fundação para a Ciência e a Tecnologia) through the grant SFRH/BD/128657/2017 and the projects PTDC/EMS-TEC/5422/2014_ADAPTPROSTHESIS and UID/EEA/04436/2019

Engineering the elastic modulus of NiTi cellular structures fabricated by selective laser melting

Nickel-titanium (NiTi) cellular structures are a very promising solution to some issues related to orthopaedic implant failure. These structures can be designed and fabricated to simultaneously address a combination of mechanical and physical properties, such as elastic modulus, porosity, wear and corrosion resistance, biocompatibility and appropriate biological environment. This ability can enhance the modest interaction currently existing between metallic dense implants and surrounding bone tissue, allowing long-term successful orthopaedic implants. For that purpose, NiTi cellular structures with different levels of porosity intended to reduce the elastic modulus were designed, modelled, selective laser melting (SLM) fabricated and characterized. Significant differences were found between the CAD design and the SLM-produced NiTi structures by performing systematic image analysis. This work proposes designing guidelines to anticipate and correct the systematic differences between CAD and produced structures. Compressive tests were carried out to estimate the elastic modulus of the produced structures and finite element analyses were performed, for comparison purposes. Linear correlations were found for the dimensions, porosity, and elastic modulus when comparing the CAD design with the SLM structures. The produced NiTi structures exhibit elastic moduli that match that of bone tissue, which is a good indication of the potential of these structures in orthopaedic implants.This work was supported by FCT (Fundação para a Ciência e Tecnologia) through the grant SFRH/BD/128657/2017 and the projects POCI-01-0145-FEDER-030353 (SMARTCUT), NORTE 01–0145_FEDER000018-HAMaBICo, UID/EEA/04436/2019 and UID/Multi/04044/2019

A potential signature for muscle-invasive tumors

Funding: This work was supported by the Astellas European Foundation Uro-Oncology Grant 2014; JABA RECORDATI Urology 2011 - Portuguese Society of Urology; Portuguese Foundation for Science and Technology (Strategic Project: PEst-C/SAU/UI3282/2013 and UID/NEU/04539/2013); GAI/FMUC and Santander Totta (Ref. FreitasGomes04.01.13) and Center of Investigation in Environment, Genetics and Oncobiology (CIMAGO), Portugal (Ref. 14/12). Margarida FerreiraTeixeira benefits from a PhD scholarship from the Portuguese Foundation for Science and Technology (Reference SFRH/BD/77314/2011).Striking evidence associates cancer stem cells (CSCs) to the high recurrence rates and poor survival of patients with muscle-invasive bladder cancer (BC). However, the prognostic implication of those cells in risk stratification is not firmly established, mainly due to the functional and phenotypic heterogeneity of CSCs populations, as well as, to the conflicting data regarding their identification based on a single specific marker. This emphasizes the need to exploit putative CSC-related molecular markers with potential prognostic significance in BC patients. This study aimed to isolate and characterize bladder CSCs making use of different functional and molecular approaches. The data obtained provide strong evidence that muscle-invasive BC is enriched with a heterogeneous stem-like population characterized by enhanced chemoresistance and tumor initiating properties, able to recapitulate the heterogeneity of the original tumor. Additionally, a logistic regression analysis identified a 2-gene stem-like signature (SOX2 and ALDH2) that allows a 93% accurate discrimination between non-muscle-invasive and invasive tumors. Our findings suggest that a stemness-related gene signature, combined with a cluster of markers to more narrowly refine the CSC phenotype, could better identify BC patients that would benefit from a more aggressive therapeutic intervention targeting CSCs population.publishersversionpublishe

Resistance to neurotoxic insecticides in populations of the coffee leafminer Leucoptera coffeella

Coffee leafminer Leucoptera coffeella is an important pest on coffee. The continued use of chemicals can result in loss of efficacy and selection of leafminer-resistant populations. We aimed to identify L. coffeella populations resistant to old and new neurotoxic insecticides in regions of Brazil. We collected seven populations of L. coffeella in Brazil. Low levels of resistance were observed for the insecticides chlorantraniliprole (1.02-3.23 times), abamectin (1.19-4.80 times), and deltamethrin (1.05-5.35 times). High resistance levels were observed for profenofos (65.3-522 times) and chlorpyrifos (4.53-18.63 times). We conclude that Brazilian L. coffeella populations showed greater resistance to organophosphate insecticides. Furthermore, resistance may be associated with the distance between the coffee-producing regions

Multi-material NiTi-PEEK hybrid cellular structures by selective laser melting and hot pressing: tribological characterization

In this study, a multi-material NiTi-PEEK cellular structured solution was designed, produced and characterized targeting orthopedic applications. For that purpose, Selective Laser Melting (SLM) technique was used to produce NiTi cellular structures with different open-cell sizes and wall thicknesses. Hot Pressing (HP) technique was used to introduce PEEK in the open-cells of NiTi structures to obtain multi-material components. Morphological characterization showed that the selected SLM processing parameters were suited to achieve high-quality parts without significant defects. Tribological characterization proved an enhanced wear resistance to the multimaterial specimens when compared with the mono-material NiTi structures. These multi-material structures are a promising solution for providing a customized stiffness and superior wear resistance to NiTi structures to be integrated in innovative orthopedic designs.This work was supported by FCT (Fundação para a Ciência e a Tecnologia) through the grant SFRH/BD/140191/2018 and by project NORTE 01–0145_FEDER-000018-HAMaBICo. Additionally, this work is supported by FCT with the reference project UID/EEA/04436/2019

Thermodiluition cardiac output measurements

The purpose of this paper is to review the aspects concerning the invasive hemodynamic monitoring of the Swan-Ganz catheter. This routine, at the bedside, will be analysed regarding its indications, its insertion techniques, the checking of this position ¾  through the surveillance of the pressure waves and the pulmonary capillary wedge pressure, and the thorax radiography ¾  and its steps for the hemodynamic measurements, examining the main error factors that can be perpetrated, and the possible complications succeeding that procedure.    O objetivo deste artigo é revisar todos os aspectos envolvidos na monitorização hemodinâmica invasiva do uso do cateter de Swan-Ganz. Esta prática, à beira do leito, será analisada em termos da sua indicação, da sua técnica de introdução, da verificação do seu posicionamento ¾ através do acompanhamento das ondas de pressão e de encunhamento, e da radiografia do tórax ¾  e do procedimento para as medidas hemodinâmicas, discutindo-se os principais fatores de erros que podem ser cometidos e as possíveis complicações do uso desse procedimento.   &nbsp

Inflammation and adipose tissue: effects of progressive load training in rats

<p>Abstract</p> <p>Introduction</p> <p>Cytokines (IL-6, IL-10 and TNF-α) are increased after exhaustive exercise in the rat retroperitoneal (RPAT) and mesenteric adipose tissue (MEAT) pads. On the other hand, these cytokines show decreased expression in these depots in response to a chronic exercise protocol. However, the effect of exercise with overload combined with a short recovery period on pro- and anti-inflammatory cytokine expression is unknown. In the present study, we investigated the regulation of cytokine production in the adipose tissue of rats after an overtraining-inducing exercise protocol.</p> <p>Methods</p> <p>Male Wistar rats were divided into four groups: Control (C), Trained (Tr), Overtrained (OT) and recovered overtrained (R). Cytokines (IL-6, TNF-α and IL-10) levels and Toll Like Receptor 4 (TLR4), Nuclear Factor kBp65 (NF-kBp65), Hormone Sensitive Lipase (HSL) and, Perilipin protein expression were assessed in the adipose tissue. Furthermore, we analysed plasma lipid profile, insulin, testosterone, corticosterone and endotoxin levels, and liver triacylglycerol, cytokine content, as well as apolipoprotein B (apoB) and TLR4 expression in the liver.</p> <p>Results</p> <p>OT and R groups exhibited reduced performance accompanied by lower testosterone and increased corticosterone and endotoxin levels when compared with the control and trained groups. IL-6 and IL-10 protein levels were increased in the adipose tissue of the group allowed to recover, in comparison with all the other studied groups. TLR-4 and NF-kBp65 were increased in this same group when compared with both control and trained groups. The protein expression of HSL was increased and that of Perilipin, decreased in the adipose in R in relation to the control. In addition, we found increased liver and serum TAG, along with reduced apoB protein expression and IL-6 and IL-10 levels in the of R in relation to the control and trained groups.</p> <p>Conclusion</p> <p>In conclusion, we have shown that increases in pro-inflammatory cytokines in the adipose tissue after an overtraining protocol may be mediated via TLR-4 and NF-kBp65 signalling, leading to an inflammatory state in this tissue.</p

Pathogenetic mechanisms of sepsis and their therapeutics implications

Este artigo apresenta uma revisão recente e objetiva dos principais mecanismos fisiopatológicos envolvidos na sepse, destacando o papel do endotélio vascular e a produção das diversas citocinas. Define a síndrome da resposta inflamatória sistêmica (SIRS) e a sepse, nos seus diversos graus de acometimento sistêmico. Mostra as disfunções produzidas pela sepse, nos diversos sistemas orgânicos, correlacionando-as com sua manifestação clínica, laboratorial e aos dados de monitorização hemodinâmica invasiva. Ao mesmo tempo, fornece as linhas gerais para o diagnóstico, avaliação da gravidade, monitorização e implicações terapêuticas, bem como as tendências terapêuticas atuais.This article presents a recent and objetive review of the pathogenetic mechanisms involved in sepsis, particularly the endothelial and mediators (citokines) role. It presents definitions for systemic inflammatory response syndrome and sepsis with its continuum of clinical and pathophysiologic severity. The organics dysfunctions were showed with its clinical, laboratorial and hemodynamics manifestations. The basic principles of management were discussed as well as new therapeutic approaches