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3,211 result(s) for "Javier Fernández, José"
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I-AUV Docking and Panel Intervention at Sea
The use of commercially available autonomous underwater vehicles (AUVs) has increased during the last fifteen years. While they are mainly used for routine survey missions, there is a set of applications that nowadays can be only addressed by manned submersibles or work-class remotely operated vehicles (ROVs) equipped with teleoperated arms: the intervention applications. To allow these heavy vehicles controlled by human operators to perform intervention tasks, underwater structures like observatory facilities, subsea panels or oil-well Christmas trees have been adapted, making them more robust and easier to operate. The TRITON Spanish founded project proposes the use of a light-weight intervention AUV (I-AUV) to carry out intervention applications simplifying the adaptation of these underwater structures and drastically reducing the operational cost. To prove this concept, the Girona 500 I-AUV is used to autonomously dock into an adapted subsea panel and once docked perform an intervention composed of turning a valve and plugging in/unplugging a connector. The techniques used for the autonomous docking and manipulation as well as the design of an adapted subsea panel with a funnel-based docking system are presented in this article together with the results achieved in a water tank and at sea.
Allocentric Spatial Memory Performance in a Virtual Reality-Based Task is Conditioned by Visuospatial Working Memory Capacity
Traditionally, the medial temporal lobe has been considered a key brain region for spatial memory. Nevertheless, executive functions, such as working memory, also play an important role in complex behaviors, such as spatial navigation. Thus, the main goal of this study is to clarify the relationship between working memory capacity and spatial memory performance. Spatial memory was assessed using a virtual reality-based procedure, the Boxes Room task, and the visual working memory with the computer-based Change Localization Task. One hundred and twenty-three (n = 123) participants took part in this study. Analysis of Covariance (ANCOVA) revealed a statistically significant relationship between working memory capacity and spatial abilities. Thereafter, two subgroups n = 60, were formed according to their performance in the working memory task (1st and 4th quartiles, n = 30 each). Results demonstrate that participants with high working memory capacity committed fewer mistakes in the spatial task compared to the low working memory capacity group. Both groups improved their performance through repeated trials of the spatial task, thus showing that they could learn spatial layouts independent of their working memory capacity. In conclusion, these findings support that spatial memory performance is directly related to working memory skills. This could be relevant for spatial memory assessment in brain lesioned patients.
Endoplasmic reticulum stress sensor IRE1α enhances IL-23 expression by human dendritic cells
Human monocyte-derived dendritic cells (DCs) exposed to pathogen-associated molecular patterns (PAMPs) undergo bioenergetic changes that influence the immune response. We found that stimulation with PAMPs enhanced glycolysis in DCs, whereas oxidative phosphorylation remained unaltered. Glucose starvation and the hexokinase inhibitor 2-deoxy-d-glucose (2-DG) modulated cytokine expression in stimulated DCs. Strikingly, IL23A was markedly induced upon 2-DG treatment, but not during glucose deprivation. Since 2-DG can also rapidly inhibit protein N-glycosylation, we postulated that this compound could induce IL-23 in DCs via activation of the endoplasmic reticulum (ER) stress response. Indeed, stimulation of DCs with PAMPs in the presence of 2-DG robustly activated inositol-requiring protein 1α (IRE1α) signaling and to a lesser extent the PERK arm of the unfolded protein response. Additional ER stressors such as tunicamycin and thapsigargin also promoted IL-23 expression by PAMP-stimulated DCs. Pharmacological, biochemical, and genetic analyses using conditional knockout mice revealed that IL-23 induction in ER stressed DCs stimulated with PAMPs was IRE1α/X-box binding protein 1-dependent upon zymosan stimulation. Interestingly, we further evidenced PERK-mediated and CAAT/enhancer-binding protein β-dependent trans-activation of IL23A upon lipopolysaccharide treatment. Our findings uncover that the ER stress response can potently modulate cytokine expression in PAMP-stimulated human DCs.
Hospitalizations for Major Cardiovascular Events in Patients Aged 75 Years or Older with Chronic Coronary Syndrome for the Whole Life Span
Background/Objectives: Limited information exists on the burden of major cardiovascular morbidity in elderly patients with chronic coronary syndrome (CCS). Our objective was to investigate the cumulative incidence of lifetime hospitalizations for major cardiovascular events (MCE) in patients aged 75 years or older with CCS and to identify clinical predictors of these events. Methods: All consecutive outpatients aged 75 years or older with CCS seen in two consultations at a tertiary hospital between 2000 and 2008 were included in a prospective study and followed until death. All MCEs requiring admission (hospitalizations for heart failure (HF), acute myocardial infarction, and stroke) were recorded, and the cumulative incidence of each event and the combination of all events was calculated, considering death without admission as a competing event. Results: A total of 414 patients were selected (mean age was 79 ± 4 years, 36% women). After a 22-year follow-up (median 7 years, p25–75 4–11), 198 patients (48%) experienced at least one MCE, the most common being hospitalization for HF (122 patients had 209 hospitalizations). The 10 and 20-year cumulative incidence was 41% (95% CI 36–46%) and 48% (43–53%) for any event. In multivariate analysis, independent predictors of hospitalization for MCE were hypertension (HR 1.58 [95% CI:1.15–2.18], p = 0.005), diabetes (HR 1.38 [1.03–1.85], p = 0.031), prior HF (HR 2.52 [1.59–4.01], p < 0.0005), and atrial fibrillation (HR:1.68 [1.13–2.50], p = 0.011). Conclusions: Nearly half of elderly patients with CCS were hospitalized for MCE during their lifetime. HF was the most common event. Several clinical variables could be useful to stratify the risk of events.
New Polyether Triterpenoids from Laurencia viridis and Their Biological Evaluation
The red seaweed Laurencia viridis is a rich source of secondary metabolites derived from squalene. New polyethers, such as iubol (2), 22-hydroxy-15(28)-dehydrovenustatriol (3), 1,2-dehydropseudodehydrothyrsiferol (4), and secodehydrothyrsiferol (5) have been isolated and characterized from this alga. The structures were determined through the interpretation of NMR spectroscopic data and the relative configuration was proposed on the basis of NOESY spectrum and biogenetic considerations. All new compounds exhibited significant cytotoxic activity against a panel of cancer cell lines.
Studies on Polyethers Produced by Red Algae
Two novel squalene-derived triterpenes, spirodehydrovenustatriol (3) and 14-keto-dehydrothyrsiferol (4) were isolated from the red alga Laurencia viridis, together with two new and unusual C17 terpenoids, adejen A (5) and B (6). These truncated structures possess structural similarities with other known squalene metabolites and their biogenetic origin has been proposed on the basis of an oxidative process of the squalene skeleton. All the structures were elucidated by extensive use of 2D NMR spectroscopic methods.
LOS DISCOS DE ORO DEL MUSEO ARQUEOLOGICO DE ASTURIAS: ALGUNAS OBSERVACIONES SOBRE LA ORFEBRERIA PREHISTORICA
Se presenta un estudio detallado de dos discos de oro de procedencia desconocida que permanecen depositados desde mediados del s. XX en el Museo Arqueológico de Asturias. Pese a la abundante bibliografía sobre estas piezas, hasta el momento no se había realizado un análisis arqueométrico y arqueometalúrgico de las mismas. Los resultados permiten inferir observaciones interesantes acerca de su composición, manufactura y secuencia tecnológica de elaboración, así como sobre la posible procedencia del oro, confirmando, con los paralelos reconocidos para la decoración de estas placas, de una clara raigambre atlántica.
Staurosporine from Streptomyces sanyensis activates Programmed Cell Death in Acanthamoeba via the mitochondrial pathway and presents low in vitro cytotoxicity levels in a macrophage cell line
Recently, the search for novel therapeutic agents against Acanthamoeba species has been focused on the evaluation of natural resources. Among them, marine microorganisms have risen as a source of bioactive compounds with the advantage of the ability to obtain unlimited and constant amounts of the compounds in contrast to other natural sources such as plants. Furthermore, marine actinomycetes have recently been reported as highly rich in bioactive agents including salinosporamides, xiamycines, indolocarbazoles, naphtyridines, phenols, dilactones such as antimycines and macrolides among others. In this study, staurosporine (STS) was isolated from a strain of Streptomyces sanyensis and tested against Acanthamoeba to characterize the therapeutic potential of STS against this protozoan parasite. We have established that STS is active against both stages of the Acanthamoeba life cycle, by the activation of Programmed Cell Death via the mitochondrial pathway of the trophozoite. We have also established that STS has relatively low toxicity towards a macrophage cell line. However, previous studies have highlighted higher toxicity levels induced on other vertebrate cell lines and future research to lower these toxicity issues should be developed.
Sclerin, a New Cytotoxic Cyclononapeptide from Annona scleroderma
A new cytotoxic cyclononapeptide, sclerin, cyclo(–Dab1–Ser2–Tyr3–Gly4–Thr5–Val6–Ala7– Ile8–Pro9–) (1), was isolated from the methanol extract of the seeds of Annona scleroderma, together with the known metabolite, cyclosenegalin A, cyclo(–Pro1–Gly2–Leu3–Ser4–Ala5–Val6–Thr7–) (2). The planar structures for the two compounds were established by comprehensive analysis of NMR and ESI-HRMS data, and the absolute stereochemistry was stablished by Marfey’s method. Compound 1 showed moderate cytotoxic activity against the human prostate carcinoma cell line DU-145 at µM concentration.
Spiralyde A, an Antikinetoplastid Dolabellane from the Brown Alga Dictyota spiralis
Bioassay-guided fractionation of the antikinetoplastid extract of the brown alga Dictyota spiralis has led to the isolation of spiralyde A (1), a new dolabellane aldehyde, along with other five known related diterpenes (2–6). Their structures were determined by HRESIMS, 1D and 2D NMR spectroscopy, and comparison with data reported in the literature. The antiparasitic activity of all compounds was evaluated. Spiralyde A (1) and the known compound 3,4-epoxy-7,18-dolabelladiene (2) were the most active compounds against Leishmania amazonensis and Trypanosoma cruzi. Spiralyde A (1) was the most potent compound, comparable to benznidazole, the reference drug for trypanocidal activity.