An experimental right atrium platform to assess recirculation in hemodialysis catheters

Hemodialysis (HD) is a treatment supporting decreased kidney function, via a catheter inserted into the heart’s Right Atrium (RA). Recirculation is a source of inefficiency for treatment, where blood is dialysed again due to poor catheter design. Lab-testing is still relatively unexplored, hence, a mechanical testing system was designed with the intention of providing a consistent and repeatable environment for testing HD catheters. System geometry was composed using a Computer-Aided Design (CAD) model of a heart, with the RA scaled to appropriate dimensions, and a PolyDiMethylSiloxane (PDMS) model produced through 3D printing and negative wax casting. Pulsatile blood flow was mimicked by peristaltic pumps driving a blood analogue (BA). Recirculation was induced by adding dyed BA to the system via the catheter and measured using a colourimeter. The developed platform was initially evaluated using two catheters, demonstrating capability to accurately replicate atrial hemodynamic conditions. Two step-tipped catheters, A and B, were tested at 350 ml/min, producing recirculation values of 13.11% and 18.58%, respectively. The results exhibit the ability of the system developed to evaluate HD catheter performance, with potential to explore a wider range of tip geometries relevant to clinical preference. Furthermore, this advancement towards an anatomically accurate lab-based test system could be paired with computational methods to progress the evaluation of such medical devices and enhance their development

Layout Analysis and Optimization of Airships with Thrust-Based Stability Augmentation

Despite offering often significant advantages with respect to other flying machines, especially in terms of flight endurance, airships are typically harder to control. Technological solutions borrowed from the realm of shipbuilding, such as bow thrusters, have been largely experimented with to the extent of increasing maneuverability. More recently, also thrust vectoring has appeared as an effective solution to ameliorate maneuverability. However, with an increasing interest for high-altitude airships (HAAs) and autonomous flight and the ensuing need to reduce weight and lifting performance, design simplicity is a desirable goal. Besides saving weight, it would reduce complexity and increase time between overhauls, in turn enabling longer missions. In this perspective, an airship layout based on a set of non-tilting thrusters, optimally placed to be employed for both propulsion and attitude control, appears particularly interesting. If sufficiently effective, such configurations would reduce the need for control surfaces on aerodynamic empennages and the corresponding actuators. Clearly, from an airship design perspective, the adoption of many smaller thrusters instead of a few larger ones allows a potentially significant departure from more classical airship layouts. Where on one side attractive, this solution unlocks a number of design variables-for instance, the number of thrusters, as well as their positioning in the general layout, mutual tilt angles, etc.-to be set according simultaneously to propulsion and attitude control goals. In this paper, we explore the effect of a set of configuration parameters defining three-thrusters and four-thrusters layout, trying to capture their impact on an aggregated measure of control performance. To this aim, at first a stability augmentation system (SAS) is designed so as to stabilize the airship making use of thrusters instead of aerodynamic surfaces. Then a non-linear model of the airship is employed to test the airship in a set of virtual simulation scenarios. The analysis is carried out in a parameterized fashion, changing the values of configuration parameters pertaining to the thrusters layout so as to understand their respective effects. In a later stage, the choice of the optimal design values (i.e., the optimal layout) related to the thrusters is demanded to an optimizer. The paper is concluded by showing the results on a complete numerical test case, drawing conclusions on the relevance of certain design parameters on the considered performance, and commenting the features of an optimal configuration

An experimental right atrium platform to assess recirculation in hemodialysis catheters

Hemodialysis (HD) is a treatment supporting decreased kidney function, via a catheter inserted into the heart’s Right Atrium (RA). Recirculation is a source of inefficiency for treatment, where blood is dialysed again due to poor catheter design. Lab-testing is still relatively unexplored, hence, a mechanical testing system was designed with the intention of providing a consistent and repeatable environment for testing HD catheters. System geometry was composed using a Computer-Aided Design (CAD) model of a heart, with the RA scaled to appropriate dimensions, and a PolyDiMethylSiloxane (PDMS) model produced through 3D printing and negative wax casting. Pulsatile blood flow was mimicked by peristaltic pumps driving a blood analogue (BA). Recirculation was induced by adding dyed BA to the system via the catheter and measured using a colourimeter. The developed platform was initially evaluated using two catheters, demonstrating capability to accurately replicate atrial hemodynamic conditions. Two step-tipped catheters, A and B, were tested at 350 ml/min, producing recirculation values of 13.11% and 18.58%, respectively. The results exhibit the ability of the system developed to evaluate HD catheter performance, with potential to explore a wider range of tip geometries relevant to clinical preference. Furthermore, this advancement towards an anatomically accurate lab-based test system could be paired with computational methods to progress the evaluation of such medical devices and enhance their development

Role of cardiovascular magnetic resonance imaging in cardio-oncology

Advances in cancer therapy have led to significantly longer cancer-free survival times over the last 40 years. Improved survivorship coupled with increasing recognition of an expanding range of adverse cardiovascular effects of many established and novel cancer therapies has highlighted the impact of cardiovascular disease in this population. This has led to the emergence of dedicated cardio-oncology services that can provide pre-treatment risk stratification, surveillance, diagnosis, and monitoring of cardiotoxicity during cancer therapies, and late effects screening following completion of treatment. Cardiovascular imaging and the development of imaging biomarkers that can accurately and reliably detect pre-clinical disease and enhance our understanding of the underlying pathophysiology of cancer treatment-related cardiotoxicity are becoming increasingly important. Multi-parametric cardiovascular magnetic resonance (CMR) is able to assess cardiac structure, function, and provide myocardial tissue characterization, and hence can be used to address a variety of important clinical questions in the emerging field of cardio-oncology. In this review, we discuss the current and potential future applications of CMR in the investigation and management of cancer patients

Towards an other development (In French)

Starting from a definition of the concept of development centered on the satisfaction of the essential needs, health, education, feeding, we show that the present pattern of development, while trying to impose Western values all over the world, prevents developing countries from building their future and, on the contrary, maintains them under the domination of Occidental countries. If the liberalism carried out during the twenty last years accelerated the merchandization of the world, capitalist system in its mondialized version has to be re-examined. Maximum profit research, primacy of private economic values, competition and technical progress must be questioned. The other development wants, starting from the current situation, to take the measurement of the essential changes that we must implement as quickly as possible. Thus, in order to replace humans at the center of economic system, we have to grant a more important place to the non-commercial activities and the non-monetary relations, like gift, which implies to reconsider the unlimited growth target and to define a new measurement of wealth. We will be able to avoid the ecological disaster announced only by reintroducing ethical and moral values and by adopting with respect to technical progress a principle of reason.Capitalism, Development, Globalization, Decrease

The continuity of the International Financial Institutions’ policies: The Example of Social Welfare (In French)

The main consequence of globalization is to accelerate the process of concentrating the wealth all around the world. Nevertheless, it did not contribute to solve the contradictions of capitalism which is not able to boost a long-time accumulation. Therefore, there are tremendous pressures to privatize the public services and the systems of Social Welfare, which are now regarded as sectors of potential profit. The great international financial institutions are urging the developed countries and are forcing the under-developed ones to reform their Health and Pension systems in order to achieve a partial or total liberalization/privatization. These reforms are said to be undertaken to preserve the financial balance of the Health insurance funds and the state sponsored redistribution pension scheme which are supposedly threatened by demographic evolution, whereas private systems would be safe from this threat. We shall deal with this topic and show how far from being scientific the argument in favor of the dismantlement of Social Welfare proves to be. We shall show as well that the demographic evolution implies necessarily a modification in the distribution of the incomes at two different and hierarchically arranged levels : firstly, within the added value between wages and incomes of capital, then within total wages themselves between direct wages and benefits from Social Welfare.financial institutions, liberalization, social welfare, distribution, social relations, demography, theory of value

Combined oestrogen and progesterone for preventing miscarriage

© 2013 The Cochrane Collaboration. Background: Historically, oestrogen and progesterone were each commonly used to save threatened pregnancies. In the 1940s it was postulated that their combined use would be synergistic and thereby led to the rationale of combined therapy for women who risked miscarriage. Objectives: To determine the efficacy and safety of combined oestrogen and progesterone therapy to prevent miscarriage. Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 June 2013) CENTRAL (OVID) (The Cochrane Library 2013, Issue 6 of 12), MEDLINE (OVID) (1946 to June Week 2 2013), OLDMEDLINE (1946 to 1965), Embase (1974 to Week 25 2013), Embase Classic (1947 to 1973), CINAHL (1994 to 23 June 2013) and reference lists of retrieved studies. Selection criteria: We included randomised controlled trials that assessed the effectiveness of combined oestrogen and progesterone for preventing miscarriage. We included one stratified randomised trial and one quasi-randomised trials. Cluster-randomised trials were eligible for inclusion but none were identified. We excluded studies published only as abstracts. We included studies that compared oestrogen and progesterone versus placebo or no intervention. Data collection and analysis: Two review authors independently assessed trials for inclusion and assessed trial quality. Two review authors extracted data. Data were checked for accuracy. Main results: Two trials (281 pregnancies and 282 fetuses) met our inclusion criteria. However, the two trials had significant clinical and methodological heterogeneity such that a meta-analysis combining trial data was considered inappropriate. One trial (involving 161 pregnancies) was based on women with a history of diabetes. It showed no statistically significant difference between using combined oestrogen and progestogen and using placebo for all our proposed primary outcomes, namely, miscarriage (risk ratio (RR) 0.95, 95% confidence interval (CI) 0.32 to 2.80), perinatal death (RR 0.94, 95% CI 0.53 to 1.69) and preterm birth (less than 34 weeks of gestation) (RR 0.91, 95% CI 0.80 to 1.04). In terms of this review's secondary outcomes, use of combined oestrogen and progestogen was associated with an increased risk of maternal cancer in the reproductive system (RR 6.65, 95% CI 1.56 to 28.29). However, for the outcome of cancer other than that of the reproductive system in mothers, there was no difference between groups. Similarly, there were no differences between the combined oestrogen and progestogen group versus placebo for other secondary outcomes reported: low birthweight of less than 2500 g, genital abnormalities in the offspring, abnormalities other than genital tract in the offspring, cancer in the reproductive system in the offspring, or cancer other than of the reproductive system in the offspring. The second study was based on pregnant women who had undergone in-vitro fertilisation (IVF). This study showed no difference in the rate of miscarriage between the combined oestrogen and progesterone group and the no treatment group (RR 0.66, 95% CI 0.23 to 1.85). The study did not report on this review's other primary outcomes (perinatal death or rates of preterm birth), nor on any of our proposed secondary outcomes. Authors' conclusions: There is an insufficient evidence from randomised controlled trials to assess the use of combined oestrogen and progesterone for preventing miscarriages. We strongly recommend further research in this area

Trade relation between MERCOSUR, NAFTA, Andean community and UE15: An analysis in term of trade creation - trade deviation (In French)

This paper determines which gravity models are the best adapted to the study of the trade evolution of several economic areas and the behaviors heterogeneity of the countries that belong to these areas (fixed effect model; random effect model). Applied to the countries of UE15, NAFTA, MERCOSUR, Andean community and APEC, the retained model contains random bilateral effects and has proved to be the most suited to describe the specific bonds between different countries. It enables also to apprehend, in terms of trade creation and trade diversion, the trade relations between the countries of the reference areas and MERCOSUR in particular.Trade creation and trade deviation, Trade block Régional, Trade agreements, Gravity Models, Fixed effect model, Random effect model

ATA Nº 755 DA SESSÃO EXTRAORDINÁRIA DO CONSELHO DE UNIDADE DO CED

Ata da sessão extraordinária do Conselho de Unidade do CED, realizada no dia 22 de junho de 2023, às dez horas, realizada por videoconferência RNP

ATA Nº 766 DA SESSÃO ORDINÁRIA DO CONSELHO DE UNIDADE DO CED

Ata da sessão ordinária do Conselho de Unidade do CED, realizada no dia 23 de maio de 2024, às dez horas, realizada por videoconferência RNP