Methods for immobilizing receptors in microfluidic devices: A review

In this review article, we discuss state-of-the-art methods for immobilizing functional receptors in microfluidic devices. Strategies used to immobilize receptors in such devices are essential for the development of specific, sensitive (bio)chemical assays that can be used for a wide range of applications. In the first section, we review the principles and the chemistry of immobilization techniques that are the most commonly used in microfluidics. We afterward describe immobilization methods on static surfaces from microchannel surfaces to electrode surfaces with a particular attention to opportunities offered by hydrogel surfaces. Finally, we discuss immobilization methods on mobile surfaces with an emphasis on both magnetic and non-magnetic microbeads, and finally, we highlight recent developments of new types of mobile supports

Microscale Interfacial Polymerization on a Chip

Forming hydrogels with precise geometries is challenging and mostly done using photopolymerization, which involves toxic chemicals, rinsing steps, solvents, and bulky optical equipment. Here, we introduce a new method for in situ formation of hydrogels with a well-defined geometry in a sealed microfluidic chip by interfacial polymerization. The geometry of the hydrogel is programmed by microfluidic design using capillary pinning structures and bringing into contact solutions containing hydrogel precursors from vicinal channels. The characteristics of the hydrogel (mesh size, molecular weight cut-off) can be readily adjusted. This method is compatible with capillary-driven microfluidics, fast, uses small volumes of reagents and samples, and does not require specific laboratory equipment. Our approach creates opportunities for filtration, hydrogel functionalization, and hydrogel-based assays, as exemplified by a rapid, compact competitive immunoassay that does not require a rinsing step

Complex Nucleic Acid Hybridization Reactions inside Capillary-Driven Microfluidic Chips

Nucleic acid hybridization reactions play an important role in many (bio)chemical fields, for example, for the development of portable point‐of‐care diagnostics, and often such applications require nucleic acid‐based reaction systems that ideally run without enzymes under isothermal conditions. The use of novel capillary‐driven microfluidic chips to perform two isothermal nucleic acid hybridization reactions, the simple opening of molecular beacon structures and the complex reaction cascade of a clamped‐hybridization chain reaction (C‐HCR), is reported here. For this purpose, reagents are arranged in a self‐coalescence module (SCM) of a passive silicon microfluidic chip using inkjet spotting. The SCM occupies a footprint of ≈7 mm$^{2}$ of a ≈0.4 × 2 cm$^{2}$ microfluidic chip. By means of fluorophore‐labeled DNA probes, the hybridization reactions can be analyzed in just ≈2 min and using only ≈3 µL of the sample. Furthermore, the SCM chip offers a variety of reagent delivery options, allowing, for example, the influence of the initiator concentration on the kinetics of C‐HCR to be investigated systematically with minimal sample and time requirements. These results suggest that self‐powered microfluidic chips equipped with a SCM provide a powerful platform for performing and investigating complex reaction systems

Rapid quantitative assays for glucose-6-phosphate dehydrogenase (G6PD) and hemoglobin combined on a capillary-driven microfluidic chip

Rapid tests for glucose-6-phosphate dehydrogenase (G6PD) are extremely important for determining G6PD deficiency, a widespread metabolic disorder which triggers hemolytic anemia in response to primaquine and tafenoquine medication, the most effective drugs for the radical cure of malaria caused by Plasmodium parasites. Current point-of-care diagnostic devices for G6PD are either qualitative, do not normalize G6PD activity to the hemoglobin concentration, or are very expensive. In this work we developed a capillary-driven microfluidic chip to perform a quantitative G6PD test and a hemoglobin measurement within 2 minutes and using less than 2 μL of sample. We used a powerful microfluidic module to integrate and resuspend locally the reagents needed for the G6PD assay and controls. We also developed a theoretical model that successfully predicts the enzymatic reactions on-chip, guides on-chip reagent spotting and allows efficient integration of multiple assays in miniaturized formats with only a few nanograms of reagents

High speed solid rotor permanent magnet machines: concept and design

This paper proposes a novel solid rotor topology for an Interior Permanent Magnet (IPM) machine, adopted in this case for an aircraft starter-generator design. The key challenge in the design is to satisfy two operating conditions which are: a high torque at start and a high speed at cruise. Conventional IPM topologies which are highly capable of extended field weakening are found to be limited at high speed due to structural constraints associated with the rotor material. To adopt the IPM concept for high speed operation, it is proposed to adopt a rotor constructed from semi-magnetic stainless steel, which has a higher yield strength than laminated silicon steel. To maintain minimal stress levels and also minimize the resultant eddy current losses due to the lack of laminations, different approaches are considered and studied. Finally, to achieve a better tradeoff between the structural and electromagnetic constraints, a novel slitted approach is implemented on the rotor. The proposed rotor topology is verified using electromagnetic, static structural and dynamic structural Finite Element (FE) analyses. An experiment is performed to confirm the feasibility of the proposed rotor. It is shown that the proposed solid rotor concept for an IPM fulfils the design requirements whilst satisfying the structural, thermal and magnetic limitations

Para leer (contemporáneamente) a Marx

Síntesis de los resultados del trabajo de dos círculos de Estudio donde se había propuesto elaborar una revisión de Marx potente y productiva. El debate es sobre la vigencia de su pensamiento y la teoría marxista actual, y empieza por una obviedad no tan obvia:su persistencia. Por las formas y porqués de esa persistencia, pero también por la genealogía de su crisis y sus causas, para concluir en la dialéctica como camino para la transformación del presente.Fil: Rocca, Facundo Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Romero, Emmanuel Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Waiman, Javier Ignacio. Universidad Nacional de Quilmes. Centro de Investigaciones sobre Economía y Sociedad en la Argentina Contemporánea; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Loustaunau, Dolores. No especifíca

Probiotic Lactobacilli Isolated from Kefir Promote Down-Regulation of Inflammatory Lamina Propria T Cells from Patients with Active IBD

Ulcerative colitis and Crohn’s disease, the two main forms of inflammatory bowel disease (IBD), are immunologically mediated disorders. Several therapies are focused on activated T cells as key targets. Although Lactobacillus kefiri has shown anti-inflammatory effects in animal models, few studies were done using human mucosal T cells. The aim of this work was to investigate the immunomodulatory effects of this bacterium on intestinal T cells from patients with active IBD. Mucosal biopsies and surgical samples from IBD adult patients (n = 19) or healthy donors (HC; n = 5) were used. Lamina propria mononuclear cells were isolated by enzymatic tissue digestion, and entero-adhesive Escherichia coli-specific lamina propria T cells (LPTC) were expanded. The immunomodulatory properties of L. kefiri CIDCA 8348 strain were evaluated on biopsies and on anti-CD3/CD28-activated LPTC. Secreted cytokines were quantified by ELISA, and cell proliferation and viability were assessed by flow cytometry. We found that L. kefiri reduced spontaneous release of IL-6 and IL-8 from inflamed biopsies ex vivo. Activated LPTC from IBD patients showed low proliferative rates and reduced secretion of TNF-α, IL-6, IFN-γ and IL-13 in the presence of L. kefiri. In addition, L. kefiri induced an increased frequency of CD4+FOXP3+ LPTC along with high levels of IL-10. This is the first report showing an immunomodulatory effect of L. kefiri CIDCA 8348 on human intestinal cells from IBD patients. Understanding the mechanisms of interaction between probiotics and immune mucosal cells may open new avenues for treatment and prevention of IBD.Fil: Curciarello, Renata. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Canziani, Karina Eva. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Salto, Ileana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Barbiera Romero, Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Rocca, Andrés. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Doldan, Ivan. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Peton, Emmanuel. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Brayer, Santiago. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Sambuelli, Alicia. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Goncalves, Silvina. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Tirado, Pablo. Gobierno de la Ciudad de Buenos Aires. Hospital de Gastroenterología "Dr. Carlos B. Udaondo"; ArgentinaFil: Correa, Gustavo Javier. Hospital Interzonal General de Agudos San Martín; ArgentinaFil: Yantorno, Martín. Hospital Interzonal General de Agudos San Martín; ArgentinaFil: Garbi, Laura. Hospital Interzonal General de Agudos San Martín; ArgentinaFil: Docena, Guillermo H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; ArgentinaFil: Serradell, María de los Ángeles. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Cátedra de Microbiología General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Muglia, Cecilia Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentin

Experimentum corporis

El cuerpo no existe, esa es la intuición sobre la que se construye el artículo. El cuerpo no comparte el rango del ser ni del acto. No es un objeto en medio de otros objetos, tampoco un sujeto al lado de otros sujetos. El cuerpo no tiene consistencia, no es: insiste. Los cuerpos, cada cuerpo, es una potencia que insiste según grados diferentes. ¿Y cómo opera esa insistencia? Por imágenes; un cuerpo es una potencia de emanación de imágenes y producción del montaje abigarrado de las mismas. Esa doble operación carece de presupuestos y se hace cada vez. Un cuerpo es la experimentación de ese cada vez. El artículo intenta, por lo tanto, escribir un cuerpo, hacer un catálogo posible de sus imágenes, de sus insistencias; en ese sentido, no se trataría de un concepto ni un saber sobre el cuerpo sino, más bien, fragmentos de cuerpos, un auténtico experimentum corporisThe body does not exist; that’s the intuition in which this text is build. The body doesn’t share the rank of being or act. Is not an object among objects, neither a subject between subjects. Body doesn’t have a consistence: it insists. The body, each body, is a power that insists in different degrees. How does this insistence operate? By images; the body is a power of emanation of images and the process of mounting attached in it. That double operation lacks of specifications and is made each time. A body is the experimentation of that each time. The article tries, therefore, to write a body, to make a catalogue of it possible images, of it insistence; in this sense, it’s not about a concept or a knowledge of the body but rather fragments of bodies; an authentic experimentum corporis.Fil: Biset, Emmanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; ArgentinaFil: Conforte, Juan Manuel. Universidad Católica de Córdoba. Facultad de Filosofía y Humanidades; ArgentinaFil: Fioretti, Lorena Cintia. Universidad Católica de Córdoba. Facultad de Filosofía y Humanidades; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Humanidades. Universidad Nacional de Córdoba. Instituto de Humanidades; ArgentinaFil: la Rocca, Paula. Universidad Nacional de Córdoba. Facultad de Filosofía y Humanidades. Centro de Investigaciones María Saleme Burnichón; ArgentinaFil: Lorio, Natalia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Humanidades. Universidad Nacional de Córdoba. Instituto de Humanidades; ArgentinaFil: Maccioni, Franca. Universidad Católica de Córdoba. Facultad de Filosofía y Humanidades; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Humanidades. Universidad Nacional de Córdoba. Instituto de Humanidades; ArgentinaFil: Martínez Ramacciotti, Javier Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; ArgentinaFil: Milone, María Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Humanidades. Universidad Nacional de Córdoba. Instituto de Humanidades; ArgentinaFil: Neuburger, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Humanidades. Universidad Nacional de Córdoba. Instituto de Humanidades; ArgentinaFil: Santucci, Silvana. Universidad Católica de Córdoba. Facultad de Filosofía y Humanidades; Argentina. Universidad Nacional de Tres de Febrero. Instituto de Investigaciones en Arte y Cultura "Dr. Norberto Griffa". Programa de Estudios Latinoamericanos Contemporáneos y Comparados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Sex differences in circulating proteins in heart failure with preserved ejection fraction

Background Many patients with heart failure with preserved ejection fraction (HFpEF) are women. Exploring mechanisms underlying the sex differences may improve our understanding of the pathophysiology of HFpEF. Studies focusing on sex differences in circulating proteins in HFpEF patients are scarce. Methods A total of 415 proteins were analyzed in 392 HFpEF patients included in The Metabolic Road to Diastolic Heart Failure: Diastolic Heart Failure study (MEDIA-DHF). Sex differences in these proteins were assessed using adjusted logistic regression analyses. The associations between candidate proteins and cardiovascular (CV) death or CV hospitalization (with sex interaction) were assessed using Cox regression models. Results We found 9 proteins to be differentially expressed between female and male patients. Women expressed more LPL and PLIN1, which are markers of lipid metabolism; more LHB, IGFBP3, and IL1RL2 as markers of transcriptional regulation; and more Ep-CAM as marker of hemostasis. Women expressed less MMP-3, which is a marker associated with extracellular matrix organization; less NRP1, which is associated with developmental processes; and less ACE2, which is related to metabolism. Sex was not associated with the study outcomes (adj. HR 1.48, 95% CI 0.83–2.63), p = 0.18. Conclusion In chronic HFpEF, assessing sex differences in a wide range of circulating proteins led to the identification of 9 proteins that were differentially expressed between female and male patients. These findings may help further investigations into potential pathophysiological processes contributing to HFpEF