315 research outputs found

    La pareja masculina en el embarazo: perspectiva de gestantes atendidas en la Subred Integrada de Servicios de Salud Norte, Bogotá

    Get PDF
    Objetivo: identificar la perspectiva de las gestantes atendidas en la Subred Integrada de Servicios de Salud Norte sobre la participación de la pareja masculina en el embarazo. Metodología: se realizó un estudio cualitativo basado en 5 grupos focales con 25 gestantes entre los 15 y 32 años, atendidas en 3 centros de la Subred Integrada de Servicios de Salud Norte; los resultados se analizaron mediante el software Atlas ti 8®. Resultados: se observa interés de las gestantes por la participación de la pareja masculina en el embarazo; dan importancia al apoyo afectivo, social y económico que esta pueda ofrecer a la embarazada y al establecimiento de un vínculo afectivo con el nonato. Conclusión: en una perspectiva de humanización, los servicios de salud sexual y reproductiva están llamados a superar los estereotipos de género que excluyen a los varones de los procesos reproductivos y a crear estrategias que consideren las necesidades de los padres y sus realidades; es posible fortalecer su vinculación convocándolos a sesiones en las que sus necesidades puedan ser reconocidas

    Left atrial appendage automatic segmentation, in computed tomography images

    Get PDF
    The left atrial appendage is one of the anatomical places where most frequently blood thrombi occur. When migrating from the appendage, these thrombi, become blood emboli that, potentially, can compromise the physiology and/or anatomy of cardiac or cerebral blood vessels, being able to generate cerebrovascular events. The left atrial appendage segmentation is very difficult due, mainly, to its location and the identical densitometric information presents into of this appendage and around of the left atrium. In this paper, an automatic technique is proposed to segment this appendage with the purpose of generating important information to the procedure called left atrial appendage surgical closure. This information is linked to the volume and the diameters of the left atrial appendage. The technique consists of a digital pre-processing stage, based on filtering processes and definition of a region of interest and, of one segmentation stage that considers a clustering method. The results are promising and they allow us to calculate useful quantitative variables when characterizing the most lethal appendix of the human body represented by the mentioned appendage. These results are very important in clinical processes where both the shape and volume of this appendage are vital for detecting and monitoring some vascular diseases such as cardiac embolism, arterial hypertension and stroke, among others

    Metamorphism in TDP-43 prion-like domain determines chaperone recognition

    Full text link
    The RNA binding protein TDP-43 forms cytoplasmic inclusions via its C-terminal prion-like domain in several neurodegenerative diseases. Aberrant TDP-43 aggregation arises upon phase de-mixing and transitions from liquid to solid states, following still unknown structural conversions which are primed by oxidative stress and chaperone inhibition. Despite the well-established protective roles for molecular chaperones against protein aggregation pathologies, knowledge on the determinants of chaperone recognition in disease-related prions is scarce. Here we show that chaperones and cochaperones primarily recognize the structured elements in TDP-43´s prionlike domain. Significantly, while HSP70 and HSP90 chaperones promote TDP43 phase separation, co-chaperones from the three classes of the large human HSP40 family (namely DNAJA2, DNAJB1, DNAJB4 and DNAJC7) show strikingly different effects on TDP-43 de-mixing. Dismantling of the second helical element in TDP-43 prion-like domain by methionine sulfoxidation impacts phase separation and amyloid formation, abrogates chaperone recognition and alters phosphorylation by casein kinase-1δ. Our results show that metamorphism in the post-translationally modified TDP-43 prion-like domain encodes determinants that command mechanisms with major relevance in diseas

    Evaluación de la primera alimentación en larvas de capaz Pimelodus grosskopfii bajo condiciones de laboratorio

    Get PDF
    RESUMEN Objetivo. Evaluar el desempeño y sobrevivencia de larvas de capaz Pimelodus grosskopfii suministrando alimento vivo (Cladóceros, Copépodos y Artemia salina). Materiales y métodos. Larvas de capaz fueron ubicadas en recipientes plásticos con un volumen útil de 3 L, a una densidad de 10 larvas L-1, fueron alimentadas cuatro veces al día, durante 15 días con nauplios de Artemia recién eclosionadas, Cladóceros de los géneros Moina y Ceriodaphnia y Copépodos calanoides. Las larvas de capaz se pesaron y se midieron al inicio y al final del experimento para estimar ganancia en peso (GP), ganancia en longitud (GL), tasa de crecimiento específico (TCE), Factor de crecimiento relativo (FCR) y sobrevivencia (S) Resultados. El tratamiento que presentó los mejores resultados en GP, GL y S fue el de larvas alimentadas con nauplios de Artemia (3.8 ± 0.2 mg, 8 ± 0.7 mm y 48.3% respectivamente) seguido de los tratamientos donde adicionó cladóceros y copépodos Conclusiones. Los nauplios de Artemia fue el tratamiento que presentó los mejores resultados en las variables productivas evaluadas en larvas de P. grosskopfii al inicio de su alimentación exógena

    Evaluation of gas diffusion electrodes as detectors in amperometric hydrogen sensors

    Get PDF
    Abstract: This work is directed to the study and evaluation of gas diffusion electrodes as detectors in hydrogen sensors. Electrochemical experiments were carried out with rotating disk electrodes with a thin porous coating of the catalyst as a previous step to select useful parameters for the sensor. An experimental arrangement made in the laboratory that simulates the sensor was found appropriate to detect volumetric hydrogen percentages above 0.25% in mixtures H 2 :N 2 . The system shows a linear response for volumetric percentages of hydrogen between 0.25 and 2 %

    The coordinated action of VCP/p97 and GCN2 regulates cancer cell metabolism and proteostasis during nutrient limitation

    Get PDF
    VCP/p97 regulates numerous cellular functions by mediating protein degradation through its segregase activity. Its key role in governing protein homoeostasis has made VCP/p97 an appealing anticancer drug target. Here, we provide evidence that VCP/p97 acts as a regulator of cellular metabolism. We found that VCP/p97 was tied to multiple metabolic processes on the gene expression level in a diverse range of cancer cell lines and in patient-derived multiple myeloma cells. Cellular VCP/p97 dependency to maintain proteostasis was increased under conditions of glucose and glutamine limitation in a range of cancer cell lines from different tissues. Moreover, glutamine depletion led to increased VCP/p97 expression, whereas VCP/p97 inhibition perturbed metabolic processes and intracellular amino acid turnover. GCN2, an amino acid-sensing kinase, attenuated stress signalling and cell death triggered by VCP/p97 inhibition and nutrient shortages and modulated ERK activation, autophagy, and glycolytic metabolite turnover. Together, our data point to an interconnected role of VCP/p97 and GCN2 in maintaining cancer cell metabolic and protein homoeostasis

    Electronic Structure of Isolated Graphene Nanoribbons in Solution Revealed by Two-Dimensional Electronic Spectroscopy

    Get PDF
    Structurally well-defined graphene nanoribbons (GNRs) are nanostructures with unique optoelectronic properties. In the liquid phase, strong aggregation typically hampers the assessment of their intrinsic properties. Recently we reported a novel type of GNRs, decorated with aliphatic side chains, yielding dispersions consisting mostly of isolated GNRs. Here we employ two-dimensional electronic spectroscopy to unravel the optical properties of isolated GNRs and disentangle the transitions underlying their broad and rather featureless absorption band. We observe that vibronic coupling, typically neglected in modeling, plays a dominant role in the optical properties of GNRs. Moreover, a strong environmental effect is revealed by a large inhomogeneous broadening of the electronic transitions. Finally, we also show that the photoexcited bright state decays, on the 150 fs time scale, to a dark state which is in thermal equilibrium with the bright state, that remains responsible for the emission on nanosecond time scales

    Mechanical Strength of 17 134 Model Proteins and Cysteine Slipknots

    Get PDF
    A new theoretical survey of proteins' resistance to constant speed stretching is performed for a set of 17 134 proteins as described by a structure-based model. The proteins selected have no gaps in their structure determination and consist of no more than 250 amino acids. Our previous studies have dealt with 7510 proteins of no more than 150 amino acids. The proteins are ranked according to the strength of the resistance. Most of the predicted top-strength proteins have not yet been studied experimentally. Architectures and folds which are likely to yield large forces are identified. New types of potent force clamps are discovered. They involve disulphide bridges and, in particular, cysteine slipknots. An effective energy parameter of the model is estimated by comparing the theoretical data on characteristic forces to the corresponding experimental values combined with an extrapolation of the theoretical data to the experimental pulling speeds. These studies provide guidance for future experiments on single molecule manipulation and should lead to selection of proteins for applications. A new class of proteins, involving cystein slipknots, is identified as one that is expected to lead to the strongest force clamps known. This class is characterized through molecular dynamics simulations.Comment: 40 pages, 13 PostScript figure

    Activity-dependent Golgi satellite formation in dendrites reshapes the neuronal surface glycoproteome

    Get PDF
    © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Govind, A. P., Jeyifous, O., Russell, T. A., Yi, Z., Weigel, A., Ramaprasad, A., Newell, L., Ramos, W., Valbuena, F. M., Casler, J. C., Yan, J.-Z., Glick, B. S., Swanson, G. T., Lippincott-Schwartz, J., & Green, W. N. Activity-dependent Golgi satellite formation in dendrites reshapes the neuronal surface glycoproteome. Elife, 10, (2021): e68910, https://doi.org/10.7554/eLife.68910.Activity-driven changes in the neuronal surface glycoproteome are known to occur with synapse formation, plasticity, and related diseases, but their mechanistic basis and significance are unclear. Here, we observed that N-glycans on surface glycoproteins of dendrites shift from immature to mature forms containing sialic acid in response to increased neuronal activation. In exploring the basis of these N-glycosylation alterations, we discovered that they result from the growth and proliferation of Golgi satellites scattered throughout the dendrite. Golgi satellites that formed during neuronal excitation were in close association with endoplasmic reticulum (ER) exit sites and early endosomes and contained glycosylation machinery without the Golgi structural protein, GM130. They functioned as distal glycosylation stations in dendrites, terminally modifying sugars either on newly synthesized glycoproteins passing through the secretory pathway or on surface glycoproteins taken up from the endocytic pathway. These activities led to major changes in the dendritic surface of excited neurons, impacting binding and uptake of lectins, as well as causing functional changes in neurotransmitter receptors such as nicotinic acetylcholine receptors. Neural activity thus boosts the activity of the dendrite’s satellite micro-secretory system by redistributing Golgi enzymes involved in glycan modifications into peripheral Golgi satellites. This remodeling of the neuronal surface has potential significance for synaptic plasticity, addiction, and disease.This work was financially supported by NIH RO1 DA035430, DA044760, and DA043361 (WNG) R01 GM104010 (BSG), T32 GM007183 (FV), and Peter F McManus Foundation (WNG)
    • …
    corecore