2,388 research outputs found
Subocclusive transvenous approach of dural arteriovenous fistula
Introdução: As fístulas arteriovenosas durais (FAVd) são usualmente adquiridas e quando
apresentam drenagem venosa cortical estão associadas a um risco elevado de hemorragia. Podem
ser tratadas por embolização (transarterial ou transvenosa), cirurgicamente ou pela combinação
das duas técnicas. A embolização por via transvenosa induz uma trombose iatrogénica do seio
venoso, acarretando risco de enfarte venoso e/ou hemorragia.
Objectivo: Rever os casos de FAVd do seio lateral submetidas a embolização transvenosa. O
nosso principal objectivo é avaliar a eficácia e a morbilidade deste tipo de tratamento e o segundo
é discutir as possíveis vantagens de uma abordagem suboclusiva na primeira sessão de tratamento.
Resultados: Os autores apresentam seis casos clínicos de FAVd, cujas formas de apresentação
foram: diminuição da acuidade visual (3); sopro pulsátil no ouvido (3); cefaleias (2);
hemorragia subaracnoideia (1); hipoacusia subjectiva (1); edema da papila (1); défice motor
(1). Angiograficamente: Cognard IIa (3), IIab (2) e IV (1), todas com envolvimento dos seios
laterais. As principais aferências eram: ACE ipsilateral (6); ACI ipsilateral (6); AV ipsilateral
(6); ACE contralateral (5); AV contralateral (5); ACI contralateral (3); ACP ipsilateral (1).
O tratamento inicial foi sempre a abordagem transarterial, com resultados angiográficos aceitáveis,
embora transitórios. Posteriormente optou-se pela via transvenosa com preenchimento do seio
lateral com GDC coils. Em cinco dos doentes decidiu-se pela suboclusão, com persistência de
algumas aferências. Em quatro, a angiografia subsequente demonstrou trombose “espontânea”
do seio lateral com resolução clínica e angiográfica da doença. Num deles a trombose ocorreu
ainda durante a sessão inicial. Todos os procedimentos decorreram sem complicações e nenhum
dos doentes desenvolveu novos défices neurológicos focais.
Conclusões: A abordagem transvenosa das FAVd obteve um sucesso técnico e clínico assinalável,
sem presença de complicações. Pensamos que a suboclusão do seio venoso com coils poderá
induzir menor alteração hemodinâmica aguda, possibilitando uma trombose mais lenta,
diminuindo o risco de complicações, mas com resolução angiográfica ulterior da FAVd
Project management practices for collaborative university-industry R&D: a hybrid approach
This paper aims to help stakeholders involved in collaborative university-industry R&D initiatives by presenting a hybrid project management (PM) approach, with a set of key distinct PM practices for this particular context.
Collaborative university-industry R&D initiatives are usually organized as programs with a set of related projects associated. Therefore, a hybrid PM approach was developed based on a case study research strategy. During the large case study analysis two research methods were applied: participant observation and document analysis.
The hybrid management approach was developed based on the contingency theory, which identifies a set of 24 Must Have PM practices, and that are transversal to all projects in the program as the program governance must have to be assured. Additionally, it identifies three different sets of Nice to Have PM practices, which are optional and are dependent on the particular project context and PM approach adopted by each project team: waterfall or agile. Overall 32 Nice to Have PM practices were identified, being 15 of them agile, 3 waterfall and the 14 remaining transversal to both agile and waterfall approaches.This research is sponsored by the Portugal Incentive System for Research and Technological Development. Project in co-promotion nº 002814/2015 (iFACTORY 2015-2018) and by the FCT (SFRH/BPD/111033/2015)
A digital tool to teach circular economy: An outlook about consumption module in DiGiTOOL to CE
This research aims to discuss which topics must be considered to develop an innovative online module
course focused on consumption in the perspective of Circular Economy. The course itself will help Higher
Education Institutions to implement digital education solution into their curricula.
The Erasmus + DiGiTOOL_to_CE project - Inclusive Digital Education - a Tool to Understand Circular
Economy includes European experts from Albania, Italy, Latvia, Lithuania, and Portugal that are cocreating
different modules on the subject. This process includes content development, e-course implementation,
test on students and revision of the e-course module.
The development of a comprehensive and coherent course, using a digital platform and including
contributions from a diverse group of experts from different backgrounds and nationalities is a very
complex task, especially with all the current travel and physical interactions restrictions related with
COVID-19. It was thus necessary to use adequate platforms – as MIRO – and common templates for
modules and storyboards, in apparel with a systematic interaction between all the members.
This experience shows the potential to use all existing know-how and technological infrastructure for the
development of the competencies in different research areas and improve our interaction skills in this
international and mostly remote environment.info:eu-repo/semantics/publishedVersio
EFFECTS OF grape powder SUPPLEMENTATION ON INFLAMMATION IN hemodialysis patients.
Polyphenols and antioxidants anti-inflammatory have been considered pharmacological agents to combat oxidative stress in chronic diseases due the reduction in the formation of free radicals (FR). Hemodialysis (HD) patients have an imbalance between oxidant and antioxidant activity, with increased levels of FR and consequently an increase of lipid peroxidation, thereby raising the risk for cardiovascular disease (CVD). The beneficial health effects of grape juice or red wine for these patients have been attributed to the antioxidant activity of its polyphenols. Then, this study aimed to evaluate the effects of grape powder supplementation on inflammation and glutathione peroxidase levels in hemodialysis (HD) patients. Thirty-two HD patients from CIN, RJ, Brazil were studied and randomly into two groups: placebo group- PG (16 patients, 9 men, 52.7 ± 13.7 yrs) and experimental group EG (16 patients, 9 men, 53.0 ± 9.8 yrs). Each patient received 12g/day of powder grape with grape jelly or only grape jelly (placebo) during 5 weeks. The lipid profile, C-reactive protein (CRP) levels and glutathione peroxidase (GPx) activity were evaluated before and after supplementation (Table). The data suggest that the consumption of grape powder was effective to increase the activity of GPx and decreasing the progression the inflammation. Thus, our results indicate that grape powder plays an important role as an antioxidant agent in HD patients.Placebo GroupExperimental GroupBeforeAfterBeforeAfterCRP (mg/mL)2.6±0.22.8±0.2*2.6±0.22.6±0.2LDL-C86.3±38.894.4±34.380.5±25.082.9±22.1Total cholesterol154.6±44.9163.3±44.8143.9±29.2145.4±28.3GPx (U/g prot)17.5±9.829.1±30.719.7±20.341.0±27.7*⁎p<0.0
Production and characterization of austenitic stainless steel cast parts reinforced with WC particles fabricated by ex situ technique
In this work, austenitic stainless steel specimens were locally reinforced with WC particles. The reinforcements were fabricated via an ex situ technique based on powder technology. Mixtures of WC, Fe, and M0101 binder were cold-pressed to obtain powder compacts. After debinding and sintering, the porous WC–Fe inserts were fixed in a mold cavity, where they reacted with liquid metal. Microstructural analysis was conducted for characterization of the phases constituting the produced reinforcement zone and the bonding interface. The results revealed that the reinforcement is a graded material with compositional and microstructural gradients throughout its thickness. The zone nearest to the surface has a ferrous matrix with homogeneously distributed WC particles and (Fe,W,Cr)6C and (Fe,W,Cr)3C carbides, formed from the liquid metal reaction with the insert. This precipitation leads to austenite destabilization, which transforms into martensite during cooling. A vast dissolution of the WC particles occurred in the inner zones, resulting in more intense carbides formation. Cr-rich carbides ((Fe,Cr,W)7C3, and (Fe,Cr,W)23C6) formed in the interdendritic regions of austenite; this zone is characterized by coarse dendrites of austenite and a multi-phase interdendritic network composed of carbides. An interface free of discontinuities and porosities indicates good bonding of the reinforcement zone to stainless steel.This research was funded by FEDER through the program P2020|COMPETE, Projetos em Copromoção (project POCI-01-0247-FEDER-033417), and the program P2020|Norte2020, Programas doutorais (NORTE-08-5369-FSE-000051)
A study on a cast steel reinforced with WC-metal matrix composite
This study seeks to investigate the local reinforcement of low carbon cast steel specimens with WC–metal matrix composites (WC–MMCs), to obtain a new material effective in competing with hard alloy steels. For this purpose, a powder compact of tungsten carbide (WC) and iron (Fe) was prepared and placed in the mold cavity before casting. The reactions that occurred with the molten steel led to the formation of the WC–MMC and, consequently, to the local reinforcement of the steel. The microstructure of the WC–MMC reinforcement was characterized by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and electron backscatter diffraction (EBSD). The results showed a microstructural variation throughout the depth of the reinforcement. In the surface region, most of the original WC particles retain their polygonal morphology, but towards the base metal, the dissolution of the WC particles increased with the formation of (Fe,W)6C carbides. Closer to the base metal, dendritic eutectic carbides of (Fe,W)6C and fine (Fe,W)23C6 precipitates in a matrix of martensite were formed. The mechanical properties of the reinforcement were evaluated by hardness and ball-cratering abrasion tests. The results revealed a significant increase in hardness, being three times harder than the base metal, and a decrease of 39% in the wear rate.This research was funded by national funds through FCT - Fundação para a Ciência e a
Tecnologia, I.P., under project references UIDB/50022/2020 and UIDP/50022/2020 and by FEDER
through program P2020|Norte2020, Programas doutorais (NORTE-08-5369-FSE-000051)
Preparation and microstructural characterization of a high-Cr white cast iron reinforced with WC particles
High-chromium white cast iron (WCI) specimens locally reinforced with WC–metal matrix composites were produced via an ex situ technique: powder mixtures of WC and Fe cold-pressed in a pre-form were inserted in the mold cavity before pouring the base metal. The microstructure of the resulting reinforcement is a matrix of martensite (α’) and austenite (γ) with WC particles evenly distributed and (Fe,W,Cr)6C carbides that are formed from the reaction between the molten metal and the inserted pre-form. The (Fe,W,Cr)6C precipitation leads to the hypoeutectic solidification of the matrix and the final microstructure consists of martensite, formed from primary austenite during cooling and eutectic constituent with (Fe,Cr)7C3 and (Fe,W,Cr)6C carbides. The presence of a reaction zone with 200 µm of thickness, between the base metal and the composite should guarantee a strong bonding between these two zones.This research was funded by FEDER through the program P2020 |COMPETE, Projetos em Copromocao (project POCI-01-0247-FEDER-033417), and the program P2020|Norte2020, Programas doutorais (NORTE-08-5369-FSE-000051)
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