40 research outputs found
Endovascular Repair of Aortic Arch Graft Pseudoaneurysm Using a Duct Occluder Device With Onlay Fusion Guidance
Aortic arch pseudoaneurysms can be caused by previous surgery, infection, or trauma. In select patients with small tears and no evidence of infection, local repair can be performed using an open or endovascular technique.1 Open surgical repeat surgery has increased risks and endovascular repair has been especially appealing for the elderly, higher risk patients, and patients with multiple prior procedures.2 We have reported the use of a ductal occluder device in a patient with a large aortic arch pseudoaneurysm.3 Our patient has provided written informed consent for the report of his case details and imaging studies
Electrically Self-Healing Thermoset MWCNTs Composites Based on Diels-Alder and Hydrogen Bonds
In this work, we prepared electrically conductive self-healing nanocomposites. The material consists of multi-walled carbon nanotubes (MWCNT) that are dispersed into thermally reversible crosslinked polyketones. The reversible nature is based on both covalent (Diels-Alder) and non-covalent (hydrogen bonding) interactions. The design allowed for us to tune the thermomechanical properties of the system by changing the fractions of filler, and diene-dienophile and hydroxyl groups. The nanocomposites show up to 1 x 10(4) S/m electrical conductivity, reaching temperatures between 120 and 150 degrees C under 20-50 V. The self-healing effect, induced by electricity was qualitatively demonstrated as microcracks were repaired. As pointed out by electron microscopy, samples that were already healed by electricity showed a better dispersion of MWCNT within the polymer. These features point toward prolonging the service life of polymer nanocomposites, improving the product performance, making it effectively stronger and more reliable
Thermally Switchable Electrically Conductive Thermoset rGO/PK Self-Healing Composites
Among smart materials, self-healing is one of the most studied properties. A self-healing polymer can repair the cracks that occurred in the structure of the material. Polyketones, which are high-performance thermoplastic polymers, are a suitable material for a self-healing mechanism: a furanic pendant moiety can be introduced into the backbone and used as a diene for a temperature reversible Diels-Alder reaction with bismaleimide. The Diels-Alder adduct is formed at around 50 °C and broken at about 120 °C, giving an intrinsic, stimuli-responsive self-healing material triggered by temperature variations. Also, reduced graphene oxide (rGO) is added to the polymer matrix (1.6–7 wt%), giving a reversible OFF-ON electrically conductive polymer network. Remarkably, the electrical conductivity is activated when reaching temperatures higher than 100 °C, thus suggesting applications as electronic switches based on self-healing soft devices
Early Feasibility of Endovascular Repair of Distal Aortic Arch Aneurysms Using Patient-Specific Single Retrograde Left Subclavian Artery Branch Stent Graft
OBJECTIVE: To describe the feasibility and outcomes of endovascular repair of distal aortic arch aneurysms using a patient-specific stent graft with a pre-loaded single retrograde left subclavian artery (LSA) branch stent graft.
METHODS: We reviewed the clinical data and outcomes of consecutive patients enrolled in an ongoing prospective, non-randomized physician-sponsored investigational device exemption study to evaluate the outcomes of endovascular aortic arch repair using patient-specific arch branch stent grafts (William Cook Europe, Bjaeverskov, Denmark) between 2019 and 2022. All patients received a design with triple-wide scallop and a single retrograde LSA branch with a pre-loaded catheter.
RESULTS: There were five male patients with median age of 77 years old (72-80) treated using the single LSA branch stent graft. Technical success was achieved in all patients. Median operating time, fluoroscopy time, and total radiation dose area product were 103 (78-134) minutes, 26 (19-39) minutes, and 123 (71-270) mGy.cm
CONCLUSION: This early feasibility study demonstrates successful endovascular repair of distal aortic arch aneurysms using a patient-specific stent graft with single retrograde LSA branch without technical failures, mortality or neurological events. Larger clinical experience and longer follow-up are needed to determined effectiveness of this approach in patients who need endovascular repair with proximal extension into Zone 2
Total Transfemoral Percutaneous Endovascular Aortic Arch Repair Using 3-Vessel Inner Branch Stent-Graft
Endovascular repair has been introduced to decrease the morbidity and mortality associated with open surgical repair of aortic arch pathology. We illustrate total percutaneous transfemoral approach with a 3-vessel inner branch stent-graft to treat aortic arch aneurysm. (Level of Difficulty: Advanced.)
Para o estudo da evolução do ensino e da formação em administração educacional em Portugal
Estudos sobre a evolução do ensino de disciplinas, na formação de professores em Portugal, são recentes. O controle burocrático centralizado reteve as dimensões do controle político-administrativo. De certo modo, protegeu a esfera educativa das influências modernizantes, do capitalismo industrial e das lógicas mercantis e gerencialistas. Defendeu a educação do domínio político, da intervenção de movimentos sociais, das propagandas de ideais democráticos e da cidadania. A utilização da designação "Administração educacional" ilustra as dificuldades sentidas, ao longo dos últimos anos, em termos da construção acadêmica de uma área, seja pela falta de tradição, seja pelos antecedentes históricos.In Portugal, studies about the evolution of disciplines teaching in the teachers formation are recent. The centralized bureaucratic control has held back the dimensions of politic administrative control. In a certain way, it has protected the education against the new-fashioned influences, manufacturing capitalism, and mercantile and managerial logics. This centralized bureaucratic control has also profected the education against the politic dominion, the intervention of social movements, the advertising of democratic ideals, and against the citizenship. The use of the term "Educational administration" shows the difficulties met by the searchers along the latest years, since there is no tradiction nor historic antecedence
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio