Hemodynamic Comparison of Two Different Pediatric Aortic Cannulas

2002 ◽  
Vol 25 (9) ◽  
pp. 867-874 ◽  
Author(s):  
D. De Wachter ◽  
F. De Somer ◽  
P. Verdonck
Keyword(s):  
Equivalent Diameter ◽  
The Novel ◽  
Performance Difference ◽  
Simple Method ◽  
Pressure Drops ◽  
Turbulent Region ◽  
Significant Performance ◽  
Data Points ◽  
Aortic Cannula ◽  
Novel Concept

Any extracorporeal blood treatment requires an adequate and safe connection to the circulation. For cardiopulmonary bypass procedures, aortic and venous cannulas are utilized. However, the performance of these cannulas is not only dependent on their size (diameter), but also on their complete geometric design. In this paper two aortic cannula designs are evaluated hemodynamically for two different sizes (8, 10 Fr) both with aqueous fluids and with blood. Using the novel concept of equivalent diameter, a new performance parameter, and the theory of dynamic similarity the results obtained with different fluids can be compared. Data points of one cannula can be fitted to a parabolic equation. There is a significant performance difference between the two 8 Fr cannulas. The 10 Fr cannulas differ non-significantly except when water is used. Equivalent diameters obtained with water in the turbulent region are significantly higher than those obtained with fluids that have a higher viscosity (blood and aqueous glycerine mixture). The latter fluids have comparable viscosities and render an equal equivalent diameter. The coefficients of their proper parabolic fit lines can easily be recalculated into each other. This provides a simple method to quickly determine pressure drops in cannulas in the operating room.

scholarly journals Knowledge Graph Transfer Network for Few-Shot Recognition

2020 ◽  
Vol 34 (07) ◽  
pp. 10575-10582
Author(s):  
Riquan Chen ◽  
Tianshui Chen ◽  
Xiaolu Hui ◽  
Hefeng Wu ◽  
Guanbin Li ◽  
...  
Keyword(s):  
Information Transfer ◽  
Knowledge Graph ◽  
Propagation Mechanism ◽  
The Novel ◽  
Main Challenge ◽  
Training Samples ◽  
Proposed Model ◽  
Significant Performance ◽  
Structured Knowledge ◽  
Novel Concept

Few-shot learning aims to learn novel categories from very few samples given some base categories with sufficient training samples. The main challenge of this task is the novel categories are prone to dominated by color, texture, shape of the object or background context (namely specificity), which are distinct for the given few training samples but not common for the corresponding categories (see Figure 1). Fortunately, we find that transferring information of the correlated based categories can help learn the novel concepts and thus avoid the novel concept being dominated by the specificity. Besides, incorporating semantic correlations among different categories can effectively regularize this information transfer. In this work, we represent the semantic correlations in the form of structured knowledge graph and integrate this graph into deep neural networks to promote few-shot learning by a novel Knowledge Graph Transfer Network (KGTN). Specifically, by initializing each node with the classifier weight of the corresponding category, a propagation mechanism is learned to adaptively propagate node message through the graph to explore node interaction and transfer classifier information of the base categories to those of the novel ones. Extensive experiments on the ImageNet dataset show significant performance improvement compared with current leading competitors. Furthermore, we construct an ImageNet-6K dataset that covers larger scale categories, i.e, 6,000 categories, and experiments on this dataset further demonstrate the effectiveness of our proposed model.

In vitro hydrodynamics of the Embol-X cannula

Perfusion ◽  
2002 ◽  
Vol 17 (2) ◽  
pp. 153-156 ◽  
Author(s):  
Anja Gerdes ◽  
Thorsten Hanke ◽  
Hans-H Sievers
Keyword(s):  
In Vivo Studies ◽  
Clinical Effects ◽  
Pressure Gradients ◽  
The Novel ◽  
Flow Rates ◽  
Mock Circulation ◽  
Aortic Cannula ◽  
Novel Concept

Background: Prevention of intraoperative plaque dislodgement in patients with atherosclerotic ascending aorta by development of innovative aortic cannula designs gains growing interest in cardiac surgery. To increase knowledge about the hydrodynamics of the innovative Embol-X™ cannula, which includes an intra-aortic filter device targeting at atheromatous emboli capture, was the aim of the present study. Methods: Pressure gradients and back pressures of the Embol-X™ cannula were measured at varying flow rates in a mock circulation and compared with two commonly used single-stream cannulae. Results: At a flow rate of 5.5 l/min, pressure gradients across the Argyle™ and the RMI cannulae were 48% and 62% and back pressures 25% and 47% lower than the corresponding values across the Embol-X™ cannula. Conclusions: The novel concept of integrating a filter device may provide clinical advantages concerning neurologic outcome. Further in vivo studies seem to be desirable to obtain more information concerning the clinical effects of the Embol-X™ cannula hydrodynamics.

scholarly journals Racism and Antiracism in the Liberal International Order

2020 ◽  
pp. 1-24
Author(s):  
Zoltán I. Búzás
Keyword(s):  
International Relations ◽  
Racial Inequality ◽  
Racial Diversity ◽  
International Order ◽  
Interdisciplinary Studies ◽  
Racial Equality ◽  
The Novel ◽  
Current Regime ◽  
Novel Concept ◽  
Comprehensive Framework

Abstract Formal racial equality is a key aspect of the current Liberal International Order (LIO). It is subject to two main challenges: resurgent racial nationalism and substantive racial inequality. Combining work in International Relations with interdisciplinary studies on race, I submit that these challenges are the latest iteration of struggles between two transnational coalitions over the LIO's central racial provisions, which I call racial diversity regimes (RDRs). The traditional coalition has historically favored RDRs based on racial inequality and racial nationalism. The transformative coalition has favored RDRs based on racial equality and nonracial nationalism. I illustrate the argument by tracing the development of the liberal order's RDR as a function of intercoalitional struggles from one based on racial nationalism and inequality in 1919 to the current regime based on nonracial nationalism and limited equality. Today, racial nationalists belong to the traditional coalition and critics of racial inequality are part of the transformative coalition. The stakes of their struggles are high because they will determine whether we will live in a more racist or a more antiracist world. This article articulates a comprehensive framework that places race at the heart of the liberal order, offers the novel concept of “embedded racism” to capture how sovereignty shields domestic racism from foreign interference, and proposes an agenda for mainstream International Relations that takes race seriously.

scholarly journals Using green infrastructure to stimulate discourse with and for planning practice: experiences with fuzzy concepts from a pan-European, a national and a local perspective

2021 ◽  
Author(s):  
Rieke Hansen ◽  
Martina van Lierop ◽  
Werner Rolf ◽  
Damjana Gantar ◽  
Ina Šuklje Erjavec ◽  
...  
Keyword(s):  
Green Infrastructure ◽  
Regional Cooperation ◽  
Knowledge Exchange ◽  
Stakeholder Involvement ◽  
The Novel ◽  
Planning Practice ◽  
Regional Project ◽  
Development Processes ◽  
Guidance Documents ◽  
Novel Concept

AbstractConcepts such as green infrastructure, nature-based solutions, and ecosystem services gained popularity in recent discourses on urban planning. Despite their recognition as innovative concepts, all of them share a degree of ambiguity. Fuzziness can be a weakness but also an opportunity to shape novel concepts together with the stakeholders that are supposed to implement them in the planning practice. The paper traces concept development processes of green infrastructure through transdisciplinary knowledge exchange in three different projects, a European and a national research project and a local city-regional project as part of an EU regional cooperation project. In all projects, the green infrastructure concept evolved in different stages. Stakeholder involvement during these stages span from consultation to co-creation. The cases reveal two different approaches: concepts that are developed “for planning practice” might be based on a plethora of insight via consultation, while those “with planning practice” foster co-creation and might result in high acceptance among the involved stakeholders. Depending on the purpose of the novel concept, each approach can be beneficial and result in practice-related and operational products, such as guidance documents or planning strategies. However, the cases also show that in any new context an exchange about fuzzy concepts is not only needed but also a chance to stimulate cooperation and joint understanding about urban challenges and how to address them.

scholarly journals CD5 costimulation induces stable Th17 development by promoting IL-23R expression and sustained STAT3 activation

Blood ◽  
2011 ◽  
Vol 118 (23) ◽  
pp. 6107-6114 ◽  
Author(s):  
Jelle de Wit ◽  
Yuri Souwer ◽  
Astrid J. van Beelen ◽  
Rosa de Groot ◽  
Femke J. M. Muller ◽  
...  
Keyword(s):  
Th17 Cells ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Orphan Receptor ◽  
The Novel ◽  
Cd28 Costimulation ◽  
Th17 Differentiation ◽  
Novel Concept ◽  
Transcription 3 ◽  
Lymphocyte Receptors

Abstract IL-17–producing CD4+ T helper (Th17) cells are important for immunity against extracellular pathogens and in autoimmune diseases. The factors that drive Th17 development in human remain a matter of debate. Here we show that, compared with classic CD28 costimulation, alternative costimulation via the CD5 or CD6 lymphocyte receptors forms a superior pathway for human Th17-priming. In the presence of the Th17-promoting cytokines IL-1β, IL-6, IL-23, and transforming growth factor-β (TGF-β), CD5 costimulation induces more Th17 cells that produce higher amounts of IL-17, which is preceded by prolonged activation of signal transducer and activator of transcription 3 (STAT3), a key regulator in Th17 differentiation, and enhanced levels of the IL-17–associated transcription factor retinoid-related orphan receptor-γt (ROR-γt). Strikingly, these Th17-promoting signals critically depend on CD5-induced elevation of IL-23 receptor (IL-23R) expression. The present data favor the novel concept that alternative costimulation via CD5, rather than classic costimulation via CD28, primes naive T cells for stable Th17 development through promoting the expression of IL-23R.

scholarly journals Phylogenetic Core Groups: a promising concept in search of a consistent methodological framework

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Alberto Pascual-García
Keyword(s):  
Microbial Communities ◽  
Microbial Ecology ◽  
Environmental Conditions ◽  
The Novel ◽  
Methodological Framework ◽  
Operational Taxonomic Units ◽  
Traditional Classification ◽  
Taxonomical Classification ◽  
Novel Concept

AbstractIn this comment, we analyse the conceptual framework proposed by Aguirre de Cárcer (Microbiome 7:142, 2019), introducing the novel concept of Phylogenetic Core Groups (PCGs). This notion aims to complement the traditional classification in operational taxonomic units (OTUs), widely used in microbial ecology, to provide a more intrinsic taxonomical classification which avoids the use of pre-determined thresholds. However, to introduce this concept, the author frames his proposal in a wider theoretical framework based on a conceptualization of selection that we argue is a tautology. This blurs the subsequent formulation of an assembly principle for microbial communities, favouring that some contradictory examples introduced to support the framework appear aligned in their conclusions. And more importantly, under this framework and its derived methodology, it is not possible to infer PCGs from data in a consistent way. We reanalyse the proposal to identify its logical and methodological flaws and, through the analysis of synthetic scenarios, we propose a number of methodological refinements to contribute towards the determination of PCGs in a consistent way. We hope our analysis will promote the exploration of PCGs as a potentially valuable tool, helping to bridge the gap between environmental conditions and community composition in microbial ecology.

Development of a Method for the Prediction of Pressure-Viscosity Coefficients of Lubricating Oils Based on Free-Volume Theory

1989 ◽  
Vol 111 (1) ◽  
pp. 121-128 ◽  
Author(s):  
C. S. Wu ◽  
E. E. Klaus ◽  
J. L. Duda
Keyword(s):  
Free Volume ◽  
Good Accuracy ◽  
Temperature Relationship ◽  
Free Volume Theory ◽  
Simple Method ◽  
Lubricating Oils ◽  
Viscosity Coefficients ◽  
Data Points

A simple method based on free-volume theory to predict the pressure-viscosity coefficients of liquid lubricants has been developed. The method only requires the viscosity-temperature relationship and the viscosity at the temperature of interest. The method provides good accuracy when it was tested for 162 data points for various fluid types over wide ranges of temperature and viscosity.

Performance Benefits of R718 Turbo-Compression Cycle Using 3-Port Condensing Wave Rotors

2004 ◽  
Author(s):  
Amir A. Kharazi ◽  
Pezhman Akbari ◽  
Norbert Mu¨ller
Keyword(s):  
Performance Enhancement ◽  
The Novel ◽  
Wave Rotor ◽  
Flash Evaporation ◽  
Pressurized Water ◽  
Wave Rotors ◽  
Compression Cycle ◽  
Performance Map ◽  
Wave Compression ◽  
Novel Concept

A number of technical challenges have often hindered the economical application of refrigeration cycles using water (R718) as refrigerant. The novel concept of condensing wave rotor provides a solution for performance improvement of R718 refrigeration cycles. The wave rotor implementation can increase efficiency and reduce the size and cost of R718 units. The condensing wave rotor employs pressurized water to pressurize, desuperheat, and condense the refrigerant vapor — all in one dynamic process. In this study, the underlying phenomena of flash evaporation, shock wave compression, desuperheating, and condensation inside the wave rotor channels are described in a wave and phase-change diagram. A computer program based on a thermodynamic model is generated to evaluate the performance of R718 baseline and wave-rotor-enhanced cycles. The detailed thermodynamic approach for the baseline and the modified cycles is described. The effect of some key parameters on the performance enhancement is demonstrated as an aid for optimization. A generated performance map summarizes the findings.

scholarly journals A NOVEL SIMPLE-BASED PRESSURE-ENTHALPY COUPLING SCHEME FOR ENGINE FLOW PROBLEMS

2012 ◽  
Vol 17 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Maximilian Emans ◽  
Zoran Žunič ◽  
Branislav Basara ◽  
Sergey Frolov
Keyword(s):  
Linear Equations ◽  
Computing Time ◽  
Simple Algorithm ◽  
Variable Density ◽  
Coupling Scheme ◽  
The Novel ◽  
Simple Method ◽  
Flow Problems ◽  
Novel Method ◽  
Coupling Terms

A novel method in CFD derived from the SIMPLE algorithm is presented. Instead of solving the linear equations for each variable and the pressurecorrection equation separately in a so-called segregated manner, it relies on the solution of a linear system that comprises the discretisation of enthalpy and pressurecorrection equation which are linked through physical coupling terms. These coupling terms reflect a more accurate approximation of the density update with respect to thermodynamics (compared to standard SIMPLE method). We show that the novel method is a reasonable extension of existing CFD techniques for variable density flows based on SIMPLE. The novel method leads to a reduction of the number of iterations of SIMPLE which translates in many – but not in all – cases to a reduction in computing time. We will therefore demonstrate practical advantages and restrictions in terms of computational efficiency for industrial CFD applications in the field of piston engine simulations.

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