2,548 research outputs found

    Palaeogenomics of the Hydrocarbon Producing Microalga Botryococcus braunii.

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    Botryococcus braunii is a colonial microalga that appears early in the fossil record and is a sensitive proxy of environmental and hydroclimatic conditions. Palaeozoic Botryococcus fossils which contribute up to 90% of oil shales and approximately 1% of crude oil, co-localise with diagnostic geolipids from the degradation of source-signature hydrocarbons. However more recent Holocene sediments demonstrate no such association. Consequently, Botryococcus are identified in younger sediments by morphology alone, where potential misclassifications could lead to inaccurate paleoenvironmental reconstructions. Here we show that a combination of flow cytometry and ancient DNA (aDNA) sequencing can unambiguously identify Botryococcus microfossils in Holocene sediments with hitherto unparalleled accuracy and rapidity. The application of aDNA sequencing to microfossils offers a far-reaching opportunity for understanding environmental change in the recent geological record. When allied with other high-resolution palaeoenvironmental information such as aDNA sequencing of humans and megafauna, aDNA from microfossils may allow a deeper and more precise understanding of past environments, ecologies and migrations

    Utilizing an interim futility analysis of the OVAL study (VB-111-701/GOG 3018) for potential reduction of risk: A phase III, double blind, randomized controlled trial of ofranergene obadenovec (VB-111) and weekly paclitaxel in patients with platinum resistant ovarian cancer

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    OBJECTIVE: Report the results from a preplanned interim analysis of a phase III, double blind, randomized controlled study of ofranergene obadenovec (VB-111), a targeted anti-cancer gene therapy, in combination with paclitaxel in patients with platinum resistant ovarian cancer (PROC). METHODS: The OVAL (NCT03398655) study is an on-going study where patients are randomly assigned in a 1:1 ratio to weekly paclitaxel 80 mg/m2 with VB-111 or placebo. The protocol specifies a pre-planned unblinded futility interim analysis of CA-125 response per GCIG criteria in the first 60 evaluable patients. The futility rule determined for this analysis was that the response rate of VB-111 must be greater than the response rate of placebo by at least 10% in order to continue the study. Coincident with the interim analysis, the blinded CA-125 response rate was estimated as a proportion of the first 60 evaluable patients with CA-125 response per GCIG criteria. Post-treatment fever is provided as a possible surrogate marker of VB-111 therapy activity. RESULTS: The median age of the evaluable patients was 62 years (range 41-82); 97% had high-grade serous cancer; 58% had been treated with 3 or more previous lines of therapy, 70% received prior anti-angiogenic treatment, 43% received prior PARP inhibitors. CA-125 response in the VB-111 and weekly paclitaxel treated arm met the pre-specified interim criterion of an absolute advantage of 10% or higher compared to the control. Blinded results show a 53% CA-125 response rate (32/60) with 15% complete response (n=9). Assuming balanced randomization and an absolute advantage of 10% or higher to the VB-111 arm, it may be deducted that the response in the VB-111 treatment arm is 58% or higher. Among patients with post-treatment fever, the CA-125 response rate was 69%. CONCLUSIONS: At the time of the interim analysis, response rate findings are comparable to the responses seen in a similar patient population in the phase I/II study. The independent data and safety monitoring committee (iDSMC) recommended continuing the OVAL trial as planned. No new safety signals were identified

    Effect of crystalline disorder on quantum tunneling in the single-molecule magnet Mn12 benzoate

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    10 páginas, 9 figuras, 1 tabla.-- PACS number(s): 75.45.+j, 75.50.Xx, 75.60.Jk, 75.50.Kj.-- et al.We report a detailed study of the effects that crystalline disorder has on the magnetic relaxation and quantum tunneling of Mn12 benzoate clusters. Thanks to the absence of interstitial molecules in the crystal structure of this molecular compound, we have been able to isolate the influence of long-range crystalline disorder. For this, we compare results obtained under two extreme situations: a crystalline sample and a nearly amorphous material. The results show that crystalline disorder affects little the anisotropy, magnetic relaxation, and quantum tunneling of these materials. It follows that disorder is not a necessary ingredient for the existence of magnetic quantum tunneling. The results unveil, however, a subtle influence of crystallinity via the modification of the symmetry of dipole-dipole interactions. The faster tunneling rates measured for the amorphous material are accounted for by a narrower distribution of dipolar bias in this material, as compared with the crystalline sample.This work has been partly funded by Grants No. MAT2009-13977-C03, No. MAT2008-06542- C04, and No. CSD2007-00010 from the Spanish Ministerio de Ciencia e Innovación, and NABISUP from DGA. We acknowledge funding from Acción Integrada under Grant No. HA2006-0051 and the Network of Excellence MAGMANet. J.v.S and S.D. acknowledge the financial support of the Deutsche Forschungsgemeinschaft (DFG) and the DAAD. Ch.C. and I.I. acknowledge the Spanish Ministerio de Ciencia e Innovación.Peer reviewe

    Movement of the external ear in human embryo

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    Introduction: External ears, one of the major face components, show an interesting movement during craniofacial morphogenesis in human embryo. The present study was performed to see if movement of the external ears in a human embryo could be explained by differential growth. Methods: In all, 171 samples between Carnegie stage (CS) 17 and CS 23 were selected from MR image datasets of human embryos obtained from the Kyoto Collection of Human Embryos. The three-dimensional absolute positio

    A comparison of online versus offline gambling harm in Portuguese pathological gamblers: an empirical study

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    Over the past decade, gambling has become a very popular activity across Europe including the growth of Internet gambling. Portugal is one of the few European countries where little research has been carried out. Given the lack of studies, a Portuguese sample (N = 1,599) was surveyed concerning their online and offline gambling habits. More specifically, the aim of this study was to identify and compare from the total sample, online pathological gamblers (PGON) (n = 171) and offline pathological gamblers' (PGOF) (n = 171) characteristics, and eventual risk factors for the development of problem gambling. Results demonstrated that PGON had different profiles compared to PGOF, although there were also similarities. Situational characteristics were much more significant for PGON than PGOF (e.g., availability, accessibility, affordability), but PGOF had higher scores than PGON on factors concerning individual characteristics (e.g., intensity of feelings while gambling, depression, suicidal ideation, etc.). Findings also showed differences concerning attitudes toward responsible gambling measures. The fact that situational characteristics are more attractive to online gamblers confirms differences between PGON and PGOF and suggests that this preferred attractiveness may enhance problem gambling potential. Further research is needed to better understand the interaction between Internet situational characteristics and the individual characteristics of gamblers, as well as the profile of the growing population of gamblers that uses both online and offline modes to gamble

    Circulating microRNAs Reveal Time Course of Organ Injury in a Porcine Model of Acetaminophen-Induced Acute Liver Failure

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    Acute liver failure is a rare but catastrophic condition which can progress rapidly to multi-organ failure. Studies investigating the onset of individual organ injury such as the liver, kidneys and brain during the evolution of acute liver failure, are lacking. MicroRNAs are short, non-coding strands of RNA that are released into the circulation following tissue injury. In this study, we have characterised the release of both global microRNA and specific microRNA species into the plasma using a porcine model of acetaminophen-induced acute liver failure. Pigs were induced to acute liver failure with oral acetaminophen over 19h±2h and death occurred 13h±3h thereafter. Global microRNA concentrations increased 4h prior to acute liver failure in plasma (P<0.0001) but not in isolated exosomes, and were associated with increasing plasma levels of the damage-associated molecular pattern molecule, genomic DNA (P<0.0001). MiR122 increased around the time of onset of acute liver failure (P<0.0001) and was associated with increasing international normalised ratio (P<0.0001). MiR192 increased 8h after acute liver failure (P<0.0001) and was associated with increasing creatinine (P<0.0001). The increase in miR124-1 occurred concurrent with the pre-terminal increase in intracranial pressure (P<0.0001) and was associated with decreasing cerebral perfusion pressure (P<0.002)

    Steady-state modulation of voltage-gated K+ channels in rat arterial smooth muscle by cyclic AMP-dependent protein kinase and protein phosphatase 2B

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    Voltage-gated potassium channels (Kv) are important regulators of membrane potential in vascular smooth muscle cells, which is integral to controlling intracellular Ca2+ concentration and regulating vascular tone. Previous work indicates that Kv channels can be modulated by receptor-driven alterations of cyclic AMP-dependent protein kinase (PKA) activity. Here, we demonstrate that Kv channel activity is maintained by tonic activity of PKA. Whole-cell recording was used to assess the effect of manipulating PKA signalling on Kv and ATP-dependent K+ channels of rat mesenteric artery smooth muscle cells. Application of PKA inhibitors, KT5720 or H89, caused a significant inhibition of Kv currents. Tonic PKA-mediated activation of Kv appears maximal as application of isoprenaline (a β-adrenoceptor agonist) or dibutyryl-cAMP failed to enhance Kv currents. We also show that this modulation of Kv by PKA can be reversed by protein phosphatase 2B/calcineurin (PP2B). PKA-dependent inhibition of Kv by KT5720 can be abrogated by pre-treatment with the PP2B inhibitor cyclosporin A, or inclusion of a PP2B auto-inhibitory peptide in the pipette solution. Finally, we demonstrate that tonic PKA-mediated modulation of Kv requires intact caveolae. Pre-treatment of the cells with methyl-β-cyclodextrin to deplete cellular cholesterol, or adding caveolin-scaffolding domain peptide to the pipette solution to disrupt caveolae-dependent signalling each attenuated PKA-mediated modulation of the Kv current. These findings highlight a novel, caveolae-dependent, tonic modulatory role of PKA on Kv channels providing new insight into mechanisms and the potential for pharmacological manipulation of vascular tone
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