Literatura científica selecionada sobre o tema "Macrofluidie"

This paper presents a novel method for fabricating fluidic circuits using laser printing technology. The method allows for rapid prototyping of macrofluidic devices with control over fluid manipulation and environmental conditions. We employed a high-resolution laser cutter to etch fluidic channels into various substrates, optimizing parameters such as laser power, speed, and substrate material. Our results demonstrate excellent performance in controlling fluid flow and maintaining environmental conditions, handling a wide range of fluids and flow rates. The devices were tested in multiple settings such as with high school students and in research laboratories in universities. We tested the laser-printed macrofluidcs mechanically for durability. We present previous works in microbiology with plants, microbial, and mammalian cell lines showing reliable operation with minimal leakage and consistent fluid dynamics. The versatility and scalability of this approach make it a promising tool for advancing research and innovation in fluidics, providing a robust platform for growing, manipulating, and experimenting with diverse biological systems from cells to whole organisms. We conclude that laser-printed macrofluidics can significantly contribute to fields such as biomedical research, synthetic biology, tissue engineering, and STEM education.

We present the design of a microfluidic device that accurately and automatically pools and delivers a precise number of droplets. It will permit the interfacing of the microfluidic world to the macrofluidic world (e.g. microtiter plates) and will allow the seamless integration of droplet microfluidics into already developed robotic workflows.

Reducing production costs, known as scaling, is a significant obstacle in the advancement of cultivated meat. The cultivation process hinges on several key components, e.g., cells, media, scaffolds, and bioreactors. This study demonstrates an innovative approach, departing from traditional stainless steel or glass bioreactors, by integrating food-grade plant-based scaffolds and thermoplastic film bioreactors. While thermoplastic films are commonly used for constructing fluidic systems, conventional welding methods are cost-prohibitive and lack rapid prototyping capabilities, thus inflating research and development expenses. The developed laser welding technique facilitates contamination-free and leakproof sealing of polyethylene films, enabling the efficient fabrication of macrofluidic systems with various designs and dimensions. By incorporating food-grade plant-based scaffolds, such as rice seeded with bovine mesenchymal stem cells, into these bioreactors, this study demonstrates sterile cell proliferation on scaffolds within macrofluidic systems. This approach not only reduces bioreactor prototyping and construction costs but also addresses the need for scalable solutions in both research and industrial settings. Integrating single-use bioreactors with minimal shear forces and incorporating macro carriers such as puffed rice may further enhance biomass production in a scaled-out model. The use of food-grade plant-based scaffolds aligns with sustainable practices in tissue engineering and cultured-meat production, emphasizing its suitability for diverse applications.

Automated reaction from the system is most important in fulfilling the requirement of the intelligent control system. Hence, many related studies regarding in developing the hardware of the system such as high sensitivity of the airflow sensor in detecting the changes either in user or the environment. The effect of the fast detection of the sensor through the high sensitivity of the airflow sensor have enable the system to identify and analyze the behavior of the user in higher accuracy compared to conventional system. Within the scope of airflow sensitivity, separation between two parts in the airflow sensor in altering the velocity impact have been inquired in purpose, while a few investigations in relations to determine the pressure contour of the main parts have been explored by application of using Computational Fluid Dynamics (CFD. This simulation is performed in the ANSYS program software. Thus, this study consequently intends to be focus on detection the high sensitivity of the airflow movement by distinguishing the high and low velocity impact. The optimization the airflow sensor in this study based on design parameter also done in order to design and develop a highly sensitive airflow sensor

The development of highly selective separation processes is a focus of current research. In 2016, the German Science Foundation funded a priority program SPP 2045 “MehrDimPart—highly specific multidimensional fractionation of fine particles with technical relevance” that aims to develop new or enhance existing approaches for the separation of nano- and micrometer-sized particles. Dielectrophoretic separators achieve highly selective separations of (bio-)particles in microfluidic devices or can handle large quantities when non-selective separation is sufficient. Recently, separator designs were developed that aim to combine a high throughput and high selectivity. Here, we summarize the development from a microfluidic fast chromatographic separation via frequency modulated dielectrophoretic particle chromatography (DPC) toward a macrofluidic high throughput separation. Further, we provide a starting point for future work by providing new experimental data demonstrating for the first time the trapping of 200 nm polystyrene particles in a dielectrophoretic high-throughput separator that uses printed circuit boards as alternatives for expensive electrode arrays.

Une complication majeure de la pose d’un stent sur une plaque d’athérosclérose est la thrombose de stent, qui présente un taux de mortalité particulièrement élevé. La bithérapie antiplaquettaire, indiquée dans la prévention de cette complication, entraîne un risque important de saignement et n’est pas toujours efficace. L’objectif de ce travail de thèse a consisté à identifier les mécanismes de la thrombose de stent et à évaluer l’intérêt d’une nouvelle classe d'agents antiplaquettaires capables de la prévenir efficacement avec un risque hémorragique faible. Le développement d’un modèle macrofluidique original a permis de montrer que les stents carotidiens utilisés en clinique possèdent une thrombogénicité intrinsèque d’une part au niveau de la bifurcation, dans la lumière du vaisseau, et d’autre part au niveau des mailles en contact avec la paroi du vaisseau. Le dispositif a également mis en lumière un effet protecteur des mailles du stent sur la thrombose de stent. Enfin, le modèle a montré que le glenzocimab, un agent anti-GPVI, est aussi efficace dans la prévention de la thrombose de stent que les traitements de référence, mais sans risque de saignements
A major complication of stenting in a diseased artery is stent thrombosis, which has a particularly high mortality rate. Dual antiplatelet therapy, indicated to prevent this complication, possesses a high risk of bleeding and is not always effective. The aim of my PhD was to identify the mechanisms of stent thrombosis and to evaluate the interest of a new class of antiplatelet agents to efficiently prevent it with a low bleeding risk. The development of an original macrofluidic model has enabled us to show that the carotid stents used in clinical practice present an intrinsic thrombogenicity evidenced both at the bifurcation of a vessel where the stent meshes lie in the lumen, and around some specific places of the stent struts which are in contact with the vessel wall. The device also helped to identify a protective effect of the stent mesh, which reduces stent thrombosis. Finally, the model showed that glenzocimab, an anti-GPVI agent, is effective in preventing stent thrombosis to a similar extent than reference treatments, but with no bleeding risk

One of the most important boron minerals, colemanite is reacted with sulfuric acid to produce boric acid. During this reaction, gypsum (calcium sulfate dihydrate) is formed as a byproduct. In this study, the boric acid production was handled both in a batch and four continuously stirred slurry reactors (4-CFSSR&rsquo
s) in series system. In this reaction system there are at least three phases, one liquid and two solid phases (colemanite and gypsum). In a batch reactor all the phases have the same operating time (residence time), whereas in a continuous reactor all the phases may have different residence time distributions. The residence time of both the reactant and the product solids are very important because they affect the dissolution conversion of colemanite and the growth of gypsum crystals. The main aim of this study was to investigate the dynamic behavior of continuous flow stirred slurry reactors. By obtaining the residence time distribution of the solid and liquid components, the non-idealities in the reactors can be found. The experiments performed in the continuous flow stirred slurry reactors showed that the reactors to be used during the boric acid production experiments approached an ideal CSTR in the range of the stirring rate (500-750 rpm) studied. The steady state performance of the continuous flow stirred slurry reactors (CFSSR&rsquo
s) in series was also studied. During the studies, two colemanites having the same origin but different compositions and particle sizes were used. The boric acid production reaction consists of two simultaneous reactions, dissolution of colemanite and crystallization of gypsum. The dissolution of colemanite and the gypsum formation was followed from the boric acid and calcium ion concentrations, respectively. The effect of initial CaO/ SO42- molar ratio (1.00, 1.37 and 2.17) on the boric acid and calcium ion concentrations were searched. Also, at these initial molar ratios the colemanite feed rate was varied (5, 7.5, 10 and 15 g/min) to change the residence time of the slurry. Purity of the boric acid solution was examined in terms of the selected impurities, which were the magnesium and sulfate ion concentrations. The concentrations of them were compared at the initial molar ratios of 1.00 and 1.37 with varying colemanite feed rates. It was seen that at high initial CaO/ SO42- molar ratios the sulfate and magnesium ion concentrations decreased but the calcium ion concentration increased. The gypsum crystals formed in the reaction are in the shape of thin needles. These crystals, mixed with the insolubles coming from the mineral, are removed from the boric acid slurry by filtration. Filtration of gypsum crystals has an important role in boric acid production reaction because it affects the efficiency, purity and crystallization of boric acid. These crystals must grow to an appropriate size in the reactor. The growth process of gypsum crystals should be synchronized with the dissolution reaction. The effect of solid hold-up (0.04&ndash
0.09), defined as the volume of solid to the total volume, on the residence time of gypsum crystals was investigated and the change of the residence time (17-60 min) on the growth of the gypsum was searched. The residence time at each reactor was kept constant in each experiment as the volumes of the reactors were equal. The growth of gypsum was examined by a laser diffraction particle size analyzer and the volume weighted mean diameters of the gypsum crystals were obtained. The views of the crystals were taken under a light microscope. It was observed that the high residence time had a positive effect on the growth of gypsum crystals. The crystals had volume weighted mean diameters of even 240 µ
m. The gypsum crystal growth model was obtained by using the second order crystallization reaction rate equation. The residence time of the continuous reactors are used together with the gypsum growth model to simulate the continuous boric acid reactors with macrofluid and microfluid models. The selected residence times (20-240 min) were modeled for different number of CSTR&rsquo
s (1-8) and the PFR. The simulated models were, then verified with the experimental data. The experimentally found calcium ion concentrations checked with the concentrations found from the microfluid model. It was also calculated that the experimental data fitted the microfluid model with a deviation of 4-7%.