92 research outputs found

    31. Biopsia aspirativa transtorácica por agulha fina para o diagnóstico de lesões pulmonares

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    Transthoracic Fine-Needle Aspiration contributes for the diagnosis of pulmonary malignant and benign lesions through cytologic analysis of the obtained material.The purpose of this study was to determine indications, accuracy and safety of transthoracic fine-needle aspiration (TNA) in the evaluation of patients with pulmonary lesions.The authors made a retrospective chart review of seven hundred and forty patients submitted to TNA in our hospital, between September 1, 1998 and June 30, 2003. Three hundred and seventy four (50,5%) were outpatients. TNA procedure was performed using an ultrathin needle, guided by fluoroscopy and cytopathologic evaluation of samples was immediate in all patients. TNA was diagnostic in 72.0% patients: a diagnosis of malignancy was achieved in 81.8% of those and benign pathology was identified in 18.2%. Complications occurred in 7.8%: pneumothorax in 5,9% patients (chest tube placement required in 2,1%); haemoptysis occurred in 2.5%.We concluded that TNA has an excellent diagnostic accuracy for malignant pulmonary lesions at a low complication rate, therefore it can be safely done in outpatients

    Suitability of PLLA as piezoelectric substrates for tissue engineering evidenced by microscopy techniques

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    Since the discovery of the piezoelectric character of bone, the suitability of some piezoelectric materials have been studied for bone repair; they are thought to act like transducers converting the mechanical energy of skeletal deformation in electrical stimuli capable of controlling osteogenic growth. The mechanisms underlying this process are far from being understood and systematic studies at a local scale are required. Atomic force microscopy (AFM) is a unique way to observe phenomena at the nanoscale and liquid imaging provides a unique tool to assess biological phenomena at the nanoscale. So in this study, aiming at a better understanding of the role of piezoelectricity in the osteogenic growth, the interaction between a poled piezoelectric material, in this case poly (L-lactic) acid and an adhesion promoting protein, the fibronectin, and bone-like cells is evaluated by scanning probe microscopy and confocal laser scanning microscopy (CLSM). © Microscopy Society of America 2012.(undefined

    Multicaloric effect in a multiferroic composite of Gd-5(Si,Ge)(4) microparticles embedded into a ferroelectric PVDF matrix

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    CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOThe coupling between electric, magnetic and elastic features in multiferroic materials is an emerging field in materials science, with important applications on alternative solid-state cooling technologies, energy harvesting and sensors/actuators. In this direction, we developed a thorough investigation of a multiferroic composite, comprising magnetocaloric/magnetostrictive Gd5Si2.4Ge1.6 microparticles blended into a piezo- and pyroelectric poly(vinylidene) fluoride (PVDF) matrix. Using a simple solvent casting technique, the formation and stabilization of PVDF electroactive phases are improved when the filler content increases from 2 to 12 weight fraction (wt.%). This effect greatly contributes to the magnetoelectric (ME) coupling, with the ME coefficient alpha(ME) increasing from 0.3 V/cm.Oe to 2.2 V/cm.Oe, by increasing the amount of magnetic material. In addition, magnetic measurements revealed that the ME-coupling has influenced the magnetocaloric effect via a contribution from the electroactive polymer and hence leading to a multicaloric effect. These results contribute to the development of multifunctional systems for novel technologies.9CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO203180/2014-3This work is funded by FEDER funds through the COMPETE 2020 Programme and National Funds throught FCT -Portuguese Foundation for Science and Technology under the projects POCI-01-0145-FEDER-029454, POCI-01-0145-FEDER-032527 and UID/FIS/04564/2016. This work was also supported by NECL with the project NORTE-01-0145-FEDER-022096 and by the European Union Horizon -2020 research and innovation program under the Marie Sklodowska-Curie Grant Agreement No. 734801. The authors acknowledge K. Pirota and F. Beron for the FTIR measurements performed at Unicamp in Brazil. Special thanks to Dr. A. Aliev for help in automatizing the ME experiments at Amirkhanov Institute of Physics and the helpful discussions. Federal Fluminense University, Brazil, permanent address for MSR; Aveiro University, Portugal, temporary address during this work for MSR. VMA thanks the CNPq for the Grant No. 203180/2014-3. A.A. acknowledges Russian Science Foundation for support magnetoelectric studies (grant No. 18-79-10176). J.H. Belo thanks FCT for Grant No. SFRH/BD/88440/2012, Project PTDC/FISMA/31302/2017, and his contract No. DL57/2016 reference SFRH-BPD-87430/2012. Finally, the discussion of results has been made possible through the mobility grant provided by the 5 top 100 Russian Academic Excellence Project at the Immanuel Kant Baltic Federal University

    DIGISER. Digital Innovation in Governance and Public Service Provision

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    Digital Innovation Challenges In view of the increasingly intense pressures on the public sector to address the challenges of our time, governments and other public entities are gradually adopting digital innovation, seeking to promote quality public services. Digital technologies and capabilities create opportunities to re-organise public service inno- vation and delivery in ways that reduce cost and increase quality, proactiveness and citizen-centricity. Multilevel governance, networks and other collaboration systems (at local, regional, national and interna- tional level) are gaining importance as key drivers of this process of digital innovation and transformation. The link to the innovation ecosystem, including all sectors of activity, both private and public (e.g., academia, industry, business, citizens and governments) appears as fundamental in all phases of the creation, devel- opment, implementation and maintenance of public services and policy making. Information and communi- cation technologies are conceived as essential elements to support the creation and sustainability of these collaboration processes. In an era in which information gains relevance in the management of the territory and allows new power relations, the expectations of citizens are increasingly demanding and specific. Considering the develop- ments of recent years, such as the economic, social and health crises, the pressure placed on the resolution of global challenges is progressively transferred to the scope of cities. There are several elements that con- tribute to the importance of cities in the digital innovation transformation process namely buying- power, being closer to citizens and being able to work across different sectors. In fact, urban territories increasingly represent a greater number of citizens - in Europe, for example, they correspond to 75% of the population - have greater autonomy in management, worldwide they contribute to 80% of the global GDP and have the potential to provide a major contribution to the resolution of global challenges. The balance between change (promoted by the digital innovation strategies) and stability (driven by organi- sational inertia) needs to be handled carefully. The transformation process has to be based on a long-term strategy and to occur in a sustainable way, by focusing on learning experiences and knowledge and tech- nology transfer, while being sensitive to the local context to ensure improvement. At the European level, the Digital Transition has been considered a main goal for the next decade. The EU launched the European Green Deal and Europe Fit for the Digital Age, a twin initiative, which links green and digital transition. The vision for the EU ́s digital decade is reflected in the Digital Compass 2030 and includes 4 cardinal points: skills, government, infrastructure and Business. With the aim of having 100% of the key public services online by 2030, the digital compass ensures that digital will contribute in a positive way to improve citizens quality of life while reducing the resources spent. To support this vision, and by understanding the importance of community-led data-driven solutions and the potential of collaborative ap- proaches, several initiatives are being implemented. The Living-in.EU movement, for example, points out the European Way’ where multi-level governance and co-creation processes support the development of a cohesive digital Europe in the path towards digital transition. Another initiative contributing to this strategy is promoted by Open & Agile Smart Cities which is connecting cities through Minimal Interoperability Mech- anisms (MIMs) - “a set of practical capabilities based on open technical specifications that allow cities and communities to replicate and scale solutions globally”. The MIMs contribute to the creation of the European Single Market by providing a common technical ground for the procurement and deployment of urban data platforms and end-to-end solutions in cities

    Microfabrication of a biomimetic arcade-like electrospun scaffold for cartilage tissue engineering applications

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    Designing and fabricating hierarchical geometries for tissue engineering (TE) applications is the major challenge and also the biggest opportunity of regenerative medicine in recent years, being the in vitro recreation of the arcade-like cartilaginous tissue one of the most critical examples due to the current inefficient standard medical procedures and the lack of fabrication techniques capable of building scaffolds with the required architecture in a cost and time effective way. Taking this into account, we suggest a feasible and accurate methodology that uses a sequential adaptation of an electrospinning-electrospraying set up to construct a system comprising both fibres and sacrificial microparticles. Polycaprolactone (PCL) and polyethylene glycol were respectively used as bulk and sacrificial biomaterials, leading to a bi-layered PCL scaffold which presented not only a depth-dependent fibre orientation similar to natural cartilage, but also mechanical features and porosity compatible with cartilage TE approaches. In fact, cell viability studies confirmed the biocompatibility of the scaffold and its ability to guarantee suitable cell adhesion, proliferation and migration throughout the 3D anisotropic fibrous network. Additionally, likewise the natural anisotropic cartilage, the PCL scaffold was capable of inducing oriented cell-material interactions since the morphology, alignment and density of the chondrocytes changed relatively to the specific topographic cues of each electrospun layer.publishe

    Phenotypic Plasticity of Mouse Spermatogonial Stem Cells

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    BACKGROUND:Spermatogonial stem cells (SSCs) continuously undergo self-renewal division to support spermatogenesis. SSCs are thought to have a fixed phenotype, and development of a germ cell transplantation technique facilitated their characterization and prospective isolation in a deterministic manner; however, our in vitro SSC culture experiments indicated heterogeneity of cultured cells and suggested that they might not follow deterministic fate commitment in vitro. METHODOLOGY AND PRINCIPAL FINDINGS:In this study, we report phenotypic plasticity of SSCs. Although c-kit tyrosine kinase receptor (Kit) is not expressed in SSCs in vivo, it was upregulated when SSCs were cultured on laminin in vitro. Both Kit(-) and Kit(+) cells in culture showed comparable levels of SSC activity after germ cell transplantation. Unlike differentiating spermatogonia that depend on Kit for survival and proliferation, Kit expressed on SSCs did not play any role in SSC self-renewal. Moreover, Kit expression on SSCs changed dynamically once proliferation began after germ cell transplantation in vivo. CONCLUSIONS/SIGNIFICANCE:These results indicate that SSCs can change their phenotype according to their microenvironment and stochastically express Kit. Our results also suggest that activated and non-activated SSCs show distinct phenotypes

    Pregnancy in the mature adult mouse does not alter the proportion of mammary epithelial stem/progenitor cells

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    Introduction In humans, an early full-term pregnancy reduces lifetime breast cancer risk by up to 50% whereas a later pregnancy (>35 years old) can increase lifetime risk. Several mechanisms have been suggested, including changes in levels of circulating hormones, changes in the way the breast responds to these hormones, changes in gene expression programmes which may alter susceptibility to transformation and changes to mammary stem cell numbers or behaviour. Previous studies have shown that the mammary tissue isolated from both virgin and parous mice has the ability to repopulate a cleared mammary fat pad in transplant experiments. Limited dilution transplant assays have demonstrated that early pregnancy (at 5 weeks of age) reduces stem/progenitor cell numbers in the mouse mammary epithelium by twofold. However, the effects on stem/progenitor cell numbers in the mammary epithelium of a pregnancy in older animals have not yet been tested. Methods Mice were put through a full-term pregnancy at 9 weeks of age, when the mammary epithelium is mature. The total mammary epithelium was purified from parous 7-week post-lactation and age-matched virgin mice and analysed by flow cytometry and limiting dilution cleared fat pad transplants. Results There were no significant differences in the proportions of different mammary epithelial cell populations or numbers of CD24+/Low Sca-1- CD49fHigh cells (stem cell enriched basal mammary epithelial compartment). There was no significant difference in stem/progenitor cell frequency based on limiting dilution transplants between the parous and age-matched virgin epithelium. Conclusions Although differences between parous and virgin mammary epithelium at later time points post lactation or following multiple pregnancies cannot be ruled out, there are no differences in stem/progenitor cell numbers between mammary epithelium isolated from parous animals which were mated at 9 weeks old and virgin animals. However, a recent report has suggested that animals that were mated at 5 weeks old have a twofold reduction in stem/progenitor cell numbers. This is of interest given the association between early, but not late, pregnancy and breast cancer risk reduction in humans. However, a mechanistic connection between stem cell numbers and breast cancer risk remains to be established
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