1,890 research outputs found

    Role of extracellular matrix components and structure in new renal models in vitro

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    The extracellular matrix (ECM), a complex set of fibrillar proteins and proteoglycans, supports the renal parenchyma and provides biomechanical and biochemical cues critical for spatial-temporal patterning of cell development and acquisition of specialized functions. As in vitro models progress towards biomimicry, more attention is paid to reproducing ECM-mediated stimuli. ECM’s role in in vitro models of renal function and disease used to investigate kidney injury and regeneration is discussed. Availability, affordability, and lot-to-lot consistency are the main factors determining the selection of materials to recreate ECM in vitro. While simpler components can be synthesized in vitro, others must be isolated from animal or human tissues, either as single isolated components or as complex mixtures, such as Matrigel or decellularized formulations. Synthetic polymeric materials with dynamic and instructive capacities are also being explored for cell mechanical support to overcome the issues with natural products. ECM components can be used as simple 2D coatings or complex 3D scaffolds combining natural and synthetic materials. The goal is to recreate the biochemical signals provided by glycosaminoglycans and other signaling molecules, together with the stiffness, elasticity, segmentation, and dimensionality of the original kidney tissue, to support the specialized functions of glomerular, tubular, and vascular compartments. ECM mimicking also plays a central role in recent developments aiming to reproduce renal tissue in vitro or even in therapeutical strategies to regenerate renal function. Bioprinting of renal tubules, recellularization of kidney ECM scaffolds, and development of kidney organoids are examples. Future solutions will probably combine these technologies

    TrajPy: empowering feature engineering for trajectory analysis across domains

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    Trajectories, sequentially measured quantities that form a path, are an important presence in many different fields, from hadronic beams in physics to electrocardiograms in medicine. Trajectory anal-ysis requires the quantification and classification of curves either using statistical descriptors or physics-based features. To date, there is no extensive and user-friendly package for trajectory anal-ysis available, despite its importance and potential application across domains. We developed a free open-source python package named TrajPy as a complementary tool to empower trajectory analysis. The package showcases a friendly graphic user interface and provides a set of physical descriptors that help characterizing these intricate structures. In combina-tion with image analysis, it was already successfully applied to the study of mitochondrial motility in neuroblastoma cell lines and to the analysis of in silico models for cell migration. The TrajPy package was developed in Python 3 and released under the GNU GPL-3 license. Easy installation is available through PyPi and the development source code can be found in the repository https://github.com/ocbe-uio/TrajPy/. The package release is automatically archived under the DOI 10.5281/zenodo.3656044.Comment: 4 pages, 1 figur

    GLUT1 expression in malignant tumors and its use as an immunodiagnostic marker

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    OBJECTIVE: To analyze glucose transporter 1 expression patterns in malignant tumors of various cell types and evaluate their diagnostic value by immunohistochemistry. INTRODUCTION: Glucose is the major source of energy for cells, and glucose transporter 1 is the most common glucose transporter in humans. Glucose transporter 1 is aberrantly expressed in several tumor types. Studies have implicated glucose transporter 1 expression as a prognostic and diagnostic marker in tumors, primarily in conjunction with positron emission tomography scan data. METHODS: Immunohistochemistry for glucose transporter 1 was performed in tissue microarray slides, comprising 1955 samples of malignant neoplasm from different cell types. RESULTS: Sarcomas, lymphomas, melanomas and hepatoblastomas did not express glucose transporter 1. Fortyseven per cent of prostate adenocarcinomas were positive, as were 29% of thyroid, 10% of gastric and 5% of breast adenocarcinomas. Thirty-six per cent of squamous cell carcinomas of the head and neck were positive, as were 42% of uterine cervix squamous cell carcinomas. Glioblastomas and retinoblastomas showed membranous glucose transporter 1 staining in 18.6% and 9.4% of all cases, respectively. Squamous cell carcinomas displayed membranous expression, whereas adenocarcinomas showed cytoplasmic glucose transporter 1 expression. CONCLUSION: Glucose transporter 1 showed variable expression in various tumor types. Its absence in sarcomas, melanomas, hepatoblastomas and lymphomas suggests that other glucose transporters mediate the glycolytic pathway in these tumors. The data suggest that glucose transporter 1 is a valuable immunohistochemical marker that can be used to identify patients for evaluation by positron emission tomography scan. The function of cytoplasmic glucose transporter 1 in adenocarcinomas must be further examined

    Use of the Hospital Anxiety and Depression Scale (HADS) in a Cardiac Emergency Room – Chest Pain Unit

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    OBJECTIVE: To determine the prevalence of anxiety and depression in patients complaining of chest pain who seek a chest pain unit attendance. INTRODUCTION: Patients arriving at a Chest Pain Unit may present psychiatric disorders not identified, isolated or co-morbid to the main illness, which may interfere in the patient prognosis. METHODOLOGY: Patients were assessed by the "Hospital Anxiety and Depression Scale" as a screening instrument wile following a systematized protocol to rule out the diagnosis of acute coronary syndrome and other potentially fatal diseases. Patients with 8 or more points in the scale were considered "probable case" of anxiety or depression. RESULTS: According to the protocol, 59 (45.4%) of 130 patients studied presented Chest Pain of Determined Cause, and 71 (54.6%) presented Chest Pain of Indefinite Cause. In the former group, in which 43 (33.1%) had acute coronary syndrome, 33.9% were probable anxiety cases and 30.5% depression cases. In the second group, formed by patients without acute coronary syndrome or any clinical conditions involving greater morbidity and mortality risk, 53.5% were probable anxiety cases and 25.4% depression. CONCLUSION: The high anxiety and depression prevalence observed may indicate the need for early and specialized approach to these disorders. When coronary arterial disease is present, this may decrease complications and shorten hospital stay. When psychiatric disorder appears isolated, is possible to reduce unnecessary repeated visits to emergency room and increase patient's quality of life

    Inequality and violent crime: evidence from data on robbery and violent theft

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    This article argues that the link between income inequality and violent property crime might be spurious, complementing a similar argument in prior analysis by the author on the determinants of homicide. In contrast, Fajnzylber, Lederman & Loayza (1998; 2002a, b) provide seemingly strong and robust evidence that inequality causes a higher rate of both homicide and robbery/violent theft even after controlling for country-specific fixed effects. Our results suggest that inequality is not a statistically significant determinant, unless either country-specific effects are not controlled for or the sample is artificially restricted to a small number of countries. The reason why the link between inequality and violent property crime might be spurious is that income inequality is likely to be strongly correlated with country-specific fixed effects such as cultural differences. A high degree of inequality might be socially undesirable for any number of reasons, but that it causes violent crime is far from proven

    Assessing hydromorphological and floristic patterns along a regulated Mediterranean river : The Serpis River (Spain)

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    In the European context, several methodologies have been developed to assess the ecological status and, specifically, the hydromorphological status of running surface waters. Although these methodologies have been widely used, few studies have focused on hydrologically altered water bodies and the factors that may determine their status. In this study, the Serpis River was divided into 16 segments from the Beniarr'es dam (40 km from the river mouth) to the sea, all of which are affected by flow regulation, but with different severity. In each segment, an inventory of the flora was conducted, and hydromorphological indices (QBR, Riparian Habitat Quality Index; and IHF, River Habitat Index) were applied. The objectives of the study were (A) to identify relationships between floristic composition and QBR components and (B) between instream habitat characteristics and IHF components as well as (C) to determine the main factors controlling the floristic composition and riparian habitat quality (QBR) and the factors controlling instream habitat characteristics and heterogeneity (IHF). A cluster analysis allowed grouping sites according to their floristic composition and instream habitat characteristics, and non-metric multidimensional scaling (NMDS) was used to ordinate the sites, obtaining the biotic and instream habitat characteristics, as well as the QBR and IHF subindices, which better explained the spatial patterns. Finally, a canonical correspondence analysis (CCA) with predictor variables (geographical, hydrological, geomorphological and human pressures) indicated the main factors controlling the spatial patterns of the floristic composition, instreamhabitat characteristics, riparian habitat quality and instream habitat heterogeneity. A gradient of riparian and instream habitat quality was identified. Our results suggest that physical constraints (presence of a gorge) have protected sites from severe human impacts, resulting in good ecological quality, despite hydrological alteration. This area, where there is geomorphological control, could be potentially reclassified into a different ecotype because regular monitoring could be using incorrect references for index scores, and naturally high scores could be confused with recovery from hydrological alteration or other pressures. The sites with the worst quality were near the river mouth and were characterised by an artificial and highly variable flow regime (related to large autumnal floods and frequent human-induced periods of zero flow). This artificial flow variability as well as the presence of lateral structures in the river channel and geomorphological characteristics were identified as the main factors driving the hydromorphological and floristic pattern in this regulated river.Diversas metodologías han sido desarrolladas en el contexto europeo para evaluar el estado ecológico, y específicamente el estado hidromorfológico de las aguas superficiales. Aunque éstas han sido ampliamente utilizadas, pocos estudios se han centrado en masas de agua hidrológicamente alteradas y en los factores que condicionan su estado. En este estudio, el río Serpis fue dividido en 16 segmentos desde la presa de Beniarrés (a 40 km de la desembocadura) hasta el mar, todos ellos afectados por la regulación de caudales con distinta severidad. En cada segmento se realizó un inventario florístico y se aplicaron índices hidromorfológicos (QBR, Calidad del Bosque de Ribera, e IHF, Índice de Hábitat Fluvial). Los objetivos del estudio fueron (A) identificar relaciones entre la composición florística y los componentes del QBR, (B) entre las caracteríısticas del hábitat fluvial y los componentes del IHF, (C) determinar los principales factores que controlan la composición florística y la calidad del hábitat ripario (QBR), y las características del hábitat fluvial y su heterogeneidad (IHF). Un cluster permitió agrupar los puntos de muestreo según su composición florística y las características del hábitat fluvial, y un escalado multidimensional no-métrico (NMDS) fue usado para ordenar los puntos, obteniendo las variables bióticas y características del hábitat y los subindices del QBR e IHF, respectivamente, que explicaban mejor los patrones espaciales. Finalmente, un análisis de correspondencias canónicas (CCA) con variables predictoras (geográficas, hidrológicas, geomorfológicas y presiones humanas) indicó los principales factores que controlan los patrones espaciales de la composición florística, las características del hábitat fluvial, la calidad del hábitat ripario y la heterogeneidad del hábitat fluvial. Se identificó un gradiente de calidad del hábitat ripario y fluvial. Los resultados sugieren que las limitaciones físicas (presencia de un cañón) han protegido a los tramos de impactos humanos severos, resultando en una buena calidad ecológica a pesar de la alteración hidrológica. Esta zona podría potencialmente ser reclasificada en un ecotipo diferente, ya que un monitoreo regular podría estar usando referencias incorrectas para los índices y sus altas puntuaciones naturales se podrían estar confundiendo con una recuperación de la alteración hidrológica o de otras presiones. Los puntos de muestreo con peor calidad estuvieron cerca de la desembocadura y tuvieron un régimen de caudales alterado y muy variable. Esta variabilidad artificial del caudal, junto con la presencia de estructuras laterales en el cauce y las características geomorfológicas fueron identificadas como los principales factores determinantes del patrón hidromorfológico y florístico en este río regulado

    Desenvolvimento, Simulação e Validação de Protocolos MAC para Redes de Sensores Sem Fios

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    O estudo e implementação de redes de sensores sem fios é um campo emergente da eletrônica que está muito interligado com a internet das coisas. Juntas essas duas tecnologias possibilitam a recolha e transmissão de dados em cenários ondes redes comuns não são adequadas. Entretanto, devido às limitações usuais que são impostas aos equipamentos usados, a conservação de energia se torna indispensável para a sua utilização. Por conta disso, foram criados diversos mecanismos para redução no consumo de energia, uma grande parte das quais passa pela implementação de novos protocolos MAC. Este artigo explica como podem ser feitas implementações desse tipo de protocolo em um simulador, o que permite que se avalie o seu desempenho sem os custos associados com estudos no mundo real. Para tanto, foram comparados os simuladores mais comuns usados neste campo de estudo e o OMNeT++ foi escolhido como o mais adequado. Depois disso foi feita uma demonstração prática de como implementar um protocolo MAC nesse simulador e os resultados da simulação foram analisados.info:eu-repo/semantics/publishedVersio

    Proteome of the phytopathogen Xanthomonas citri subsp. citri: a global expression profile

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    <p>Abstract</p> <p>Background</p> <p>Citrus canker is a disease caused by <it>Xantomonas citri </it>subsp.<it>citri (Xac)</it>, and has emerged as one of the major threats to the worldwide citrus crop because it affects all commercial citrus varieties, decreases the production and quality of the fruits and can spread rapidly in citrus growing areas. In this work, the first proteome of <it>Xac </it>was analyzed using two methodologies, two-dimensional liquid chromatography (2D LC) and tandem mass spectrometry (MS/MS).</p> <p>Results</p> <p>In order to gain insight into the metabolism of <it>Xac</it>, cells were grown on two different media (<b>NB </b>- Nutrient Broth and <b>TSE </b>- Tryptone Sucrose broth enriched with glutamic acid), and proteins were proteolyzed with trypsin and examined by 2D LC-MS/MS. Approximately 39% of all predicted proteins by annotation of <it>Xac </it>were identified with their component peptides unambiguously assigned to tandem mass spectra. The proteins, about 1,100, were distributed in all annotated functional categories.</p> <p>Conclusions</p> <p>This is the first proteomic reference map for the most aggressive strain of <it>Xanthomonas </it>pathogen of all orange varieties. The compilation of metabolic pathways involved with bacterial growth showed that <it>Xac </it>expresses a complete central and intermediary metabolism, replication, transcription and translation machineries and regulation factors, distinct membrane transporters (ABC, MFS and pumps) and receptors (MCP, TonB dependent and metabolites acquisition), two-component systems (sensor and regulatory components) and response regulators. These data corroborate the growth curve <it>in vitro </it>and are the first reports indicating that many of these genome annotated genes are translated into operative in <it>Xac</it>. This proteomic analysis also provided information regarding the influence of culture medium on growth and protein expression of <it>Xac</it>.</p
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