6,180 research outputs found

    Uprolides N, O and P from the Panamanian Octocoral Eunicea succinea.

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    Three new diterpenes, uprolide N (1), uprolide O (2), uprolide P (3) and a known one, dolabellane (4), were isolated from the CH₂Cl₂-MeOH extract of the gorgonian octocoral Eunicea succinea, collected from Bocas del Toro, on the Caribbean coast of Panama. Their structures were determined using spectroscopic analyses, including 1D and 2D NMR and high-resolution mass spectrometry (HRMS) together with molecular modeling studies. Compounds 1-3 displayed anti-inflammatory properties by inhibiting production of Tumor Necrosis Factor (TNF) and Interleukin (IL)-6 induced by lipopolysaccharide (LPS) in murine macrophages

    Microbialite-like structures in Cladophora sp. (Ulvophyceae) mats from a subtropical Andean basin: ecological implications

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    The solubility equilibrium of calcite is influenced by physicochemical, climatic and biological factors. Annual cycles of exceptionally prolonged drought, in conjunction with naturally occurring diffuse organic pollution, generate the unique conditions for the precipitation of lithified carbonate structures (microbialites). The aim of this article is to analyze the possible implications of calcite precipitation produced in mats of Cladophora sp. in an Andean subtropical basin, considering it is the first time this phenomenon is described for the region. We collected samples from selected sites at the Lules River Basin, in four sampling dates between the years 2003 and 2004, within a monitoring work of 15 years. Samples were analyzed using an electron microscope and X-ray diffraction analysis. We found that Gomphonema sp. attached to Cladophora sp. contributes to precipitation of calcite and formation of microbialite like structures, in the studied area. This work presents an initial discussion of the discovery of microbialites-like structures attached to Cladophora sp. mats in a subtropical Andean stream and the environmental conditions that lead to their production, as well as the possible ecological implications of these microbialites.Fil: Fernandez, Hugo Rafael. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Biodiversidad Neotropical. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Biodiversidad Neotropical. Instituto de Biodiversidad Neotropical; ArgentinaFil: González Achem, Ana L.. Fundación Miguel Lillo. Dirección de Zoología. Instituto de Invertebrados; ArgentinaFil: Correa, M.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Albarracín, Virginia Helena. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin

    Label-free detection of nosocomial bacteria using a nanophotonic interferometric biosensor

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    Nosocomial infections are a major concern at the worldwide level. Early and accurate identification of nosocomial pathogens is crucial to provide timely and adequate treatment. A prompt response also prevents the progression of the infection to life-threatening conditions, such as septicemia or generalized bloodstream infection. We have implemented two highly sensitive methodologies using an ultrasensitive photonic biosensor based on a bimodal waveguide interferometer (BiMW) for the fast detection of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA), two of the most prevalent bacteria associated with nosocomial infections. For that, we have developed a biofunctionalization strategy based on the use of a PEGylated silane (silane-PEG-COOH) which provides a highly resistant and bacteria-repelling surface, which is crucial to specifically detect each bacterium. Two different biosensor assays have been set under standard buffer conditions: One based on a specific direct immunoassay employing polyclonal antibodies for the detection of P. aeruginosa and another one employing aptamers for the direct detection of MRSA. The biosensor immunoassay for P. aeruginosa is fast (it only takes 12 min) and specific and has experimentally detected concentrations down to 800 cfu mL (cfu: Colony forming unit). The second one relies on the use of an aptamer that specifically detects penicillin-binding protein 2a (PBP2a), a protein only expressed in the MRSA mutant, providing a photonic biosensor with the ability to identify the resistant pathogen MRSA and differentiate it from methicillin-susceptible S. aureus (MSSA). Direct, label-free, and selective detection of whole MRSA bacteria has been achieved, making possible the direct detection of also 800 cfu mL. According to the signal-to-noise (S/N) ratio of the device, a theoretical limit of detection (LOD) of around 49 and 29 cfu mL was estimated for P. aeruginosa and MRSA, respectively. Both results obtained under standard conditions reveal the great potential this interferometric biosensor device has as a versatile and specific tool for bacterial detection and quantification, providing a rapid method for the identification of nosocomial pathogens within the clinical requirements of sensitivity for the diagnosis of infections

    Galaxy cluster mass density profile derived using the submillimetre galaxies magnification bias

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    Context. The magnification bias is a gravitational lensing eect that produces an increase or decrease in the detection probability of background sources near the position of a lense. The special properties of the submillimetre galaxies (SMGs; steep source number counts, high redshift, and a very low cross-contamination with respect to the optical band) makes them the optimal background sample for magnification bias studies. Aims. We want to study the average mass density profile of tens to hundreds of clusters of galaxies acting as lenses that produce a magnification bias on the SMGs, and to estimate their associated masses and concentrations for dierent richness ranges. The cluster richness is defined as R = L200=L with L200 as the total r-band luminosity within the radius r200. Methods. The background sample is composed of SMGs observed by Herschel with 1:2 < z < 4:0 (mean redshift at 2:3) while the foreground sample is made up of galaxy clusters extracted from the Sloan Digital Sky Survey III with photometric redshifts of 0:05 < z < 0:8 (mean redshift at 0:38). Measurements are obtained by stacking the SMG–cluster pairs to estimate the crosscorrelation function using the Davis-Peebles estimator. This methodology allows us to derive the mass density profile for a wide range of angular scales, 2250 arcsec or 101300 kpc for z = 0:38, with a high radial resolution, and in particular to study the inner part of the dark matter halo (<100 kpc). In addition, we also divide the cluster sample into five bins of richness and we analyse the estimated cross-correlation data using dierent combinations of the most common theoretical mass density profiles. Results. It is impossible to fit the data with a single mass density profile at all scales: in the inner part there is a clear excess in the mass density profile with respect to the outer part that we interpret as the galactic halo of the big central galaxy. As for the outer part, the estimated average masses increase with richness from M200c = 5:8 1013 M to M200c = 51:5 1013 M (M200c = 7:1 1013 M for the total sample). With respect to the concentration parameter, its average also increases with richness from C = 0:74 to C = 1:74 (C = 1:72 for the total sample). In the small-scale regions, the obtained average masses fluctuate around M200c = 34 1013 M with average concentration values of around C 4. Conclusions. The total average masses are in perfect agreement with the mass–richness relationship estimated from the cluster catalogue. In the bins of lowest richness, the central galactic halo constitutes 40% of the total mass of the cluster and its relevance decreases for higher richness values. While the estimated average concentration values of the central galactic halos are in agreement with traditional mass–concentration relationships, we find low concentrations for the outer part. Moreover, the concentrations decrease for lower richness values, probably indicating that the group of galaxies cannot be considered to be relaxed systems. Finally, we notice a systematic lack of signal at the transition between the dominance of the cluster halo and the central galactic halo (100 kpc). This feature is also present in previous studies using dierent catalogues and/or methodologies, but is never discussed

    CHK1 expression in gastric cancer is modulated by p53 and RB1/E2F1: Implications in chemo/radiotherapy response

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    Radiation has a limited but relevant role in the adjuvant therapy of gastric cancer (GC) patients. Since Chk1 plays a critical function in cellular response to genotoxic agents, we aimed to analyze the role of Chk1 in GC as a biomarker for radiotherapy resistance. We analyzed Chk1 expression in AGS and MKN45 human GC cell lines by RT-QPCR and WB and in a small cohort of human patient’s samples. We demonstrated that Chk1 overexpression specifically increases resistance to radiation in GC cells. Accordingly, abrogation of Chk1 activity with UCN-01 and its expression with shChk1 increased sensitivity to bleomycin and radiation. Furthermore, when we assessed Chk1 expression in human samples, we found a correlation between nuclear Chk1 accumulation and a decrease in progression free survival. Moreover, using a luciferase assay we found that Chk1’s expression is controlled by p53 and RB/E2F1 at the transcriptional level. Additionally, we present preliminary data suggesting a posttranscriptional regulation mechanism, involving miR-195 and miR-503, which are inversely correlated with expression of Chk1 in radioresistant cells. In conclusion, Chk1/microRNA axis is involved in resistance to radiation in GC, and suggests Chk1 as a potential tool for optimal stratification of patients susceptible to receive adjuvant radiotherapy after surgeryThis work was supported by Instituto de Salud Carlos III–Fondo de Investigación Sanitaria (PS09/1988 to ISP; PI11-00949, pI014-1495 and Feder Funds to RP); Comunidad Autónoma de Madrid-Universidad Autónoma de Madrid (CCG10-UAM/BIO-5871 to ISP); Fundación Leticia Castillejo Castillo and Ministerio de Ciencia e Innovación (SAF2012-30862 to RSP), Spain

    Guadalfeo and Adra submarine deltas evolution in response to sediment supply variations

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    The Guadalfeo and the Adra submarine deltas off the northern coast of the Alboran Sea have been built up under the direct influence of short and mountainous rivers. The area is subjected to strong climatic seasonality, with sporadic winter torrential floods and high summer aridity. In addition numerous anthropogenic activities have affected these systems, mostly during the last two centuries. In order to decode the influence of climatic variability and anthropogenic impacts on sediment supplies during the recent past, five sediment cores were collected from the Guadalfeo and Adra submarine deltas. Benthic foraminiferal and sedimentological analyses, combined with radiocarbon dating, were performed. The impact of torrential floods alternating with periods of low rainfall or dry periods were recorded in the Adra and Guadalfeo prodeltas. Periods with low abundance of benthic foraminifera and high amounts of coarse-grained sediments, were interpreted as the result of enhanced sediment supply to the shelf triggered by major flood events. On the other hand, periods with high amounts of fine-grained sediments and high abundances of colonizers and opportunistic foraminiferal species indicate the establishment of new environments with distinct ecological constraints. These environments were driven by lower sediment supplies during low rainfall or dry periods. The most recent sedimentation seems to reflect the human interventions in the rivers basins, such as deviation of the main river courses and dams construction, which reduced the sediment input and promoted the deposition of shallow-water submarine deltas.info:eu-repo/semantics/publishedVersio

    Monitoring of RAS mutant clones in plasma of patients with RAS mutant metastatic colorectal cancer

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    Circulating tumor DNA; Liquid biopsy; Metastatic colorectal cancerADN tumoral circulante; Biopsia liquida; Cáncer colorrectal metastásicoADN tumoral circulant; Biòpsia líquida; Càncer colorectal metastàticPurpose Some patients with histologically confirmed primary mCRC and mutated RAS reported undetectable RAS mutant clones in plasma after receiving anti-VEGF treatment. The aim was to prospectively assess it with its potential therapeutic implications. Methods RAS mutant genes in solid biopsy (before first-line treatment: FOLFOX/CAPOX + bevacizumab) were compared in liquid biopsy (before second-line treatment: panitumumab + FOLFIRI), using Idylla™ system. Discordant results between solid/liquid biopsies were assessed by the next-generation sequencing (NGS) test (solid/liquid biopsies). Results Twenty-three patients were assessed (seven had RAS mutant discrepancies between solid/liquid biopsies). The NGS test confirmed that 3/23 (13%) patients had undetectable RAS mutant clones in liquid biopsy and 3/23 (13%) presented discrepancies in solid biopsy (Idylla™ system vs. NGS test). Conclusion Thirteen percentage of patients had undetectable RAS mutant clones in liquid biopsy after first-line treatment. However, some discrepancies between solid and liquid biopsies have been observed. These results suggest a need to improve accuracy of RAS analyses, especially in solid biopsies.This work was supported by Amgen S.A. Amgen did not have any role in study design; collection, analysis, and interpretation of data; writing the report; and the decision to submit the report for publication

    Modeling Sustainability Reporting with Ternary Attractor Neural Networks

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    International Conference on Mining Intelligence and Knowledge Exploration. Cluj-Napoca, Romania, December 20–22, 2018This work models the Corporate Sustainability General Reporting Initiative (GRI) using a ternary attractor network. A dataset of years evolution of the GRI reports for a world-wide set of companies was compiled from a recent work and adapted to match the pattern coding for a ternary attractor network. We compare the performance of the network with a classical binary attractor network. Two types of criteria were used for encoding the ternary network, i.e., a simple and weighted threshold, and the performance retrieval was better for the latter, highlighting the importance of the real patterns’ transformation to the three-state coding. The network exceeds the retrieval performance of the binary network for the chosen correlated patterns (GRI). Finally, the ternary network was proved to be robust to retrieve the GRI patterns with initial noise.This work has been supported by Spanish grants MINECO (http://www.mineco.gob.es/) TIN2014-54580-R, TIN2017-84452-R, and by UAMSantander CEAL-AL/2017-08, and UDLA-SIS.MG.17.02

    Influence of stress and depression on the immune system in patients evaluated in an anti-aging unit

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    Background: There is compelling evidence pointing out that stress and depression produce a dramatic impact on human well-being mainly through impairing the regular function of the immune system and producing a low-chronic inflammation status that favors the occurrence of infections, metabolic diseases, and even cancer. The present work aims to evaluate the stress/depression levels of some patients treated in an antiaging unit and detect any potential relationship with their immune system status prior of the implementation of a physical/psychological program designed to prevent health deterioration. Methods: We evaluated 48 patients (16 men and 32 women with a mean age of 55.11 ± 10.71 years) from middle-upper class from psychological and immunological points of view. In particular, we analyzed neutrophil chemotaxis and phagocytosis; lymphocyte chemotaxis and proliferation, and natural killer (NK) cell activity. Results: Women showed more depressive symptoms than men. Chemotaxis levels of lymphocytes and neutrophils in women showed a significant reduction compared with those in men. We also found a strong negative correlation between depression and NK cell function. This correlation was also significant independently of gender. Conclusion: We conclude that NK activity is affected at least by depression state, and we propose that a combined treatment consisting of cognitive behavioral therapy and physical activity programs might improve patient health deterioration
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