737 research outputs found

    Kinetics of Particles Adsorption Processes Driven by Diffusion

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    The kinetics of the deposition of colloidal particles onto a solid surface is analytically studied. We take into account both the diffusion of particles from the bulk as well as the geometrical aspects of the layer of adsorbed particles. We derive the first kinetic equation for the coverage of the surface (a generalized Langmuir equation) whose predictions are in agreement with recent simulation results where diffusion of particles from the bulk is explicitly considered.Comment: 4 page

    Pathogenic effects of maternal antinuclear antibodies during pregnancy in women with lupus

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    Lupus is an autoimmune disease that primarily affects young women of childbearing age. Fertility rates in lupus patients depend on various factors, including disease activity, nephritis, and the presence of antiphospholipid antibodies; however, after lupus patients become pregnant, different factors may affect the course of pregnancy, such as the production of autoantibodies, pre-existing renal disease, and eclampsia, among others. The placenta is a temporary hemochorial organ that prevents immunological conflict due to exposure to alloantigens at the maternal-fetal interface; placental regulatory T cells play a major role in maternal-fetal tolerance. Typically, significant amounts of maternal IgG class antibodies cross the placenta and enter the fetal circulation. This transition depends on the distribution of Fc receptors along the syncytiotrophoblast. The production of antinuclear antibodies (ANA) is a hallmark of lupus, and these autoantibodies can form immune complexes that are typically trapped in the placenta during gestation. However, the entry of ANA into the fetal circulation depends on the IgG-ANA concentration and the FcR placental density. Maternal antinuclear antibodies with anti-Ro or anti-La specificity might be pathogenic to the fetus if transfused by the placental pathway and could induce neonatal pathologies, such as neonatal lupus and congenital heart block. Here, we review the experimental and clinical data supporting a pathogenic role for maternal autoantibodies transmitted to the fetus

    Assortative and modular networks are shaped by adaptive synchronization processes

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    Modular organization and degree-degree correlations are ubiquitous in the connectivity structure of biological, technological, and social interacting systems. So far most studies have concentrated on unveiling both features in real world networks, but a model that succeeds in generating them simultaneously is needed. We consider a network of interacting phase oscillators, and an adaptation mechanism for the coupling that promotes the connection strengths between those elements that are dynamically correlated. We show that, under these circumstances, the dynamical organization of the oscillators shapes the topology of the graph in such a way that modularity and assortativity features emerge spontaneously and simultaneously. In turn, we prove that such an emergent structure is associated with an asymptotic arrangement of the collective dynamical state of the network into cluster synchronization

    La Yuyera

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    Trabajo de Conclusión de Curso III - Obra Audiovisual, presentado al Instituto Latino-Americano de Arte, Cultura e Historia da Universidad Federal de la Integración Latinoamericana, como requisito parcial à obtención do título de licenciatura en Cine y audiovisual. Orientador: Prof. Dr. Bernardo Teodorico Costa Souza y Co-Orientador: Prof. Dr. Eduardo Dias FonsecaSegún encuestas realizadas por el sitio web de noticias El Surtidor, actualmente, en Paraguay el 80% de los casos de violencia contra la mujer se dan en el entorno familiar. “El agresor es alguien que te conoce”, es una de las frases contundentes que el periódico digital enfatiza dentro del testimonio de Elida Favole, directora de prensa de la Fiscalía y responsable de la oficina de género. Este es, lamentablemente, un tema que afecta no solamente a las mujeres paraguayas, sino a miles en toda Latinoamérica. La Yuyera, desde su posición como obra cinematográfica, busca contribuir con los esfuerzos por alcanzar una toma de conciencia como sociedad sobre esta problemática tan grave; esto, a partir de una historia donde el abuso y la opresión son parte del día a día que sufre una adolescente a manos de su abuelo, un anciano machista que no le permite ir al colegio y la obliga a trabajar por las mañanas como yuyera y por las tardes como limpiadora doméstica. Es así que con el uso de diferentes simbolismos se pretende con este cortometraje, transmitir un mensaje de lucha a la sociedad, utilizando la muerte del opresor como un sinónimo de un alto a las conductas violentas; al mismo tiempo que se destaca el empoderamiento femenino como sinónimo de fuerza, confianza y valor para enfrentar la cruel realidad actua

    Ruteo de vehículos escolares: caso de estudio de la Universidad Autónoma de Coahuila

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    En este trabajo se proponen un conjunto de nuevas rutas de transporte para dar servicio a la comunidad estudiantil actual del Campus Arteaga de la Universidad Autónoma de Coahuila atendiendo a la dispersidad de los estudiantes en la zona metropolitana de Saltillo. Se analiza un caso de estudio con la información de una Facultad, considerando 380 estudiantes y 46 paradas correspondientes a las colonias de Saltillo. El problema se formula matemáticamente como un modelo lineal entero mixto, el cual es resuelto a través de un optimizador comercial. Con el modelo sólo es posible resolver a optimalidad instancias de 10 paradas y 50 estudiantes, por lo que se diseñó un algoritmo heurístico constructivo híbrido basado en el algoritmo de Clarke y Wright, en donde la factibilidad de una solución se verifica al resolver una versión simplificada del modelo matemático. Se implementan dos estrategias para reducir el tiempo de cómputo del algoritmo heurístico y se reportan las nuevas rutas propuestas, así como algunas recomendaciones para facilitar la construcción de las instancias del problema

    Newcomer and receiving communities' perspectives on Latino immigrant acculturation in community B

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    Purpose of the project: to understand the perceptions of both Latino newcomers and receiving community members regarding the integration of Latino immigrants in rural communities in the Midwest. This study is part of a larger participatory action research project that seeks to examine effective strategies for integrating Latino newcomers into rural communities.Includes bibliographical references

    New 4-(N-cinnamoylbutyl)aminoacridines as potential multi-stage antiplasmodial leads

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    A novel family of 4-aminoacridine derivatives was obtained by linking this heteroaromatic core to different trans-cinnamic acids. The 4-(N-cinnamoylbutyl)aminoacridines obtained exhibited in vitro activity in the low- or sub-micromolar range against (i) hepatic stages of Plasmodium berghei, (ii) erythrocytic forms of Plasmodium falciparum, and (iii) early and mature gametocytes of Plasmodium falciparum. The most active compound, having a meta-fluorocinnamoyl group linked to the acridine core, was 20- and 120-fold more potent, respectively, against the hepatic and gametocyte stages of Plasmodium infection than the reference drug, primaquine. Moreover, no cytotoxicity towards mammalian and red blood cells at the concentrations tested was observed for any of the compounds under investigation. These novel conjugates represent promising leads for the development of new multi-target antiplasmodials.Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved

    The ESCRT-III machinery participates in the production of extracellular vesicles and protein export during Plasmodium falciparum infection

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    Malaria is a disease caused by Plasmodium parasites that is still a leading cause of death in many low-income countries, and for which currently available therapeutic strategies are not succeeding in its control, let alone eradication. An interesting feature observed after Plasmodium invasion is the increase of extracellular vesicles (EVs) generated by parasitized red blood cells (pRBCs), which lack a vesicular trafficking that would explain EV production. Here, by combining different approaches, we demonstrated the participation of the endosomal sorting complex required for transport (ESCRT) machinery from Plasmodium falciparum in the production of EVs in pRBCs. Moreover, we were able to detect ESCRT-III proteins adjacent to the membrane of the host and in EVs purified from a pRBC culture, which shows the export of these proteins and their participation in EV production. Finally, the disruption of an ESCRT-III associated gene, Pfvps60, led to a significant reduction in the amount of EVs. Altogether, these results confirm ESCRT-III participation in EV production and provide novel information on the P. falciparum protein export mechanisms, which can be used for the development of new therapeutic strategies against malaria, based on the disruption of EV formation and trafficking

    Apoptosis and Redistribution of the Ro Autoantigen in Balb/c Mouse Like in Subacute Cutaneous Lupus Erythematosus

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    In subacute cutaneous lupus eryhematosus (SCLE) the cutaneous antigens constitute the main source of Ro and La autoantigens. The aim of this investigation was to demonstrate if UV light increases the availability of Ro autoantigen in the skin, also the blocking effect of Ac-DEVD-CMK a caspase inhibitor was assessed. For this purpose newborn Balb/c mice were UVB irradiated (5–30 mJ/cm2) equivalent to a moderate to severe sunburn. Animals were injected with monoclonal anti-Ro antibodies from SCLE patients. Apoptosis was also induced by anti-Fas antibody injection. Skin samples were examined by direct immunofluoresence, by TUNEL, and the expression of caspase 3 by RT-PCR. Major findings of present studies were: 1. UVB irradiation and anti-Fas induced apoptosis of keratinocytes. 2. Apoptosis redistribute the Ro antigen on cell surface and is better triggered by Ro antibody. 3. The caspase 3 inhibitor Ac-DEVD-CMK decreases the availability of Ro autoantigen in epidermis and prevents deposition of anti-Ro. In conclusion, the caspase pathway would be blocked to avoid anti-Ro deposition along skin; this finding would be a prospect in the treatment of SCLE patients

    Apoptosis and cell proliferation: the paradox of salivary glands in sjögren’s disease

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    Este estudo avalia a apoptose e a proliferação nas glândulas salivares dos doentes com Síndroma de Sjögren primária. Métodos: A apoptose foi estudada por imunohistoquímica utilizando anticorpos monoclonais anti- -Fas, FasL e Caspase 3 e as características apoptóticas por TUNEL. Os estudos foram executados em vinte e quatro glândulas salivares minor de doentes com Síndroma de Sjögren primária e num igual número de controlos. A proliferação foi avaliada com anticorpos monoclonais anti-PCNA e anti-Ki67. Resultados:Todas as glândulas salivares dos doentes com Sjögren apresentavam moléculas apoptoticas no epitélio dos ductos salivares, e menos no tecido acinar, consequentemente a presença do caspase 3, Fas/FasL eram concordantes com a expressão da apoptose por TUNEL. Os marcadores de proliferação foram encontrados nas células inflamatórias presentes, mas não no epitélio ductal nem nos acinos. A expressão de marcadores de apoptose ou de proliferação nos tecidos das biopsias dos controlos foi escassa. Conclusão: Os dados actuais sugerem que as células do epitélio ductal e dos acinos das glândulas salivares dos doentes com doença de Sjögren têm aumento da apoptose. A proliferação foi observada principalmente no infiltrado celular linfóide. Em conjunto, estes eventos constituem um paradoxo biológico relacionado com o processo inflamatório das glândulas salivares na Síndrome de Sjögren.Aim: To assess apoptosis and proliferation in salivary glands of patients with primary Sjögren’s syndrome. Methods: Studies were performed in twenty four minor salivary glands from patients with primary Sjögren’s syndrome and an equal number of controls. Apoptosis was studied by immunohistochemistry using monoclonal antibodies anti-Fas, FasL and Caspase 3 and apoptotic features by TUNEL. Proliferation was assessed with monoclonal anti-PCNA and anti-Ki67 antibodies. Results: All salivary glands from Sjögren’s display apoptotic molecules along the epithelia of salivary ducts, and in a smaller amount in acinar tissue. The presence of Caspase 3, Fas/FasL was concordant with the expression of apoptosis by TUNEL. Proliferation markers were encountered in inflammatory emigrant cells, but not in ductal epithelia nor in acini. Control biopsies poorly expressed apoptotic or proliferation markers. Conclusion: Present data suggests that the ductal epithelial and acinar cells of salivary glands from Sjögren’s disease patients exhibit increased apoptosis. Proliferation was mainly observed in infiltrating lymphoid cells. Both events constitute a biological paradox related to the inflammatory process of salivary glands in Sjögren’s disease
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