535 research outputs found

    Avoided crossing resonances: structural and dynamical aspects

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    We examine structural and dynamical properties of quantum resonances associated with an avoided crossing and identify the parameter shifts where these properties attain maximal or extreme values, first at a general level, and then for a two-level system coupled to a harmonic oscillator, of the type commonly found in quantum optics. Finally the results obtained are exemplified and applied to optimize the fidelity and speed of quantum gates in trapped ions.Comment: 4 pages, 1 figur

    Numerical study of a thrombus migration risk in aneurysm after coil embolization in patient cases: FSI modelling

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    Purpose There are still many challenges for modelling a thrombus migration process in aneurysms. The main novelty of the present research lies in the modelling of aneurysm clot migration process in a realistic cerebral aneurysm, and the analysis of forces sufered by clots inside an aneurysm, through transient FSI simulations. Methods The blood fow has been modelled using a Womersley velocity profle, and following the Carreau viscosity model. Hyperelastic Ogden model has been used for clot and isotropic linear elastic model for the artery walls. The FSI coupled model was implemented in ANSYS® software. The hemodynamic forces sufered by the clot have been quantifed using eight diferent clot sizes and positions inside a real aneurysm. Results The obtained results have shown that it is almost impossible for clots adjacent to aneurysm walls, to leave the aneurysm. Nevertheless, in clots positioned in the centre of the aneurysm, there is a real risk of clot migration. The risk of migration of a typical post-coiling intervention clot in an aneurysm, in contact with the wall and occupying a signifcant percentage of its volume is very low in the case studied, even in the presence of abnormally intense events, associated with sneezes or impacts. Conclusions The proposed methodology allows evaluating the clot migration risk, vital for evaluating the progress after endovascular interventions, it is a step forward in the personalized medicine, patient follow-up, and helping the medical team deciding the optimal treatment.Universidade de Vigo/CISU

    Fe speciation in Iron modified natural zeolites as sustainable environmental catalysts

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    Natural purified mordenite from Palmarito de Cauto (ZP) deposit, Cuba, was subjected to a hydrothermal ion exchange process in acid medium with Fe2+ or Fe3+ salts (Fe2+ZP and Fe3+ZP). The set of samples was characterized regarding their textural properties, morphology, and crystallinity, and tested in the NO reduction with CO/C3H6. Infrared spectroscopy coupled with NO as a probe molecule was used to give a qualitative description of the Fe species’ nature and distribution. The exchange process caused an increase in the iron loading of the samples and a redistribution, resulting in more dispersed Fe2+ and Fe3+ species. When contacted with the NO probe, Fe2+ZP showed the highest intensity of nitrosyl bands, assigned to NO adducts on isolated/highly dispersed Fe2+/Fe3+ extra-framework sites and FexOy clusters. This sample is also characterized by the highest NO sorption capacity and activity in NO reduction. Fe3+ZP showed a higher intensity of nitrosonium (NO+) species, without a correlation to NO storage and conversion, pointing to the reactivity of small FexOy aggregates in providing oxygen atoms for the NO to NO+ reaction. The same sites are proposed to be responsible for the higher production of CO2 observed on this sample, and thus to be detrimental to the activity in NO SCR

    Low Power Design of MPPT Circuit Using Power Down System in 65nm CMOS Process

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    In the field of light energy harvesting, a great amount of power is wasted when the voltage of the photovoltaic cells does not reach the maximum power point at which the storage will charge at its most efficient manner. The most common solution is to build a maximum power point tracking (MPPT) circuit. However, this still needs improvement with very low energy produced indoor. Thus, aiming to reduce the power consumption of the conventional MPPT system, this study implemented a power down system that turns off idle blocks; hence, improving the performance of the conventional MPPT circuit. From several MPPT techniques, this study implemented the Fractional Open Circuit Voltage Method (FOCV), which has a lower cost and simple circuitry, neglecting the use of a microcontroller. Conventional FOCV-based MPPT systems are composed of a sampling circuit that sets the maximum power point voltage (VMPP) from the sampled open circuit voltage (VOC); and a comparator which assures that the accurate VMPP is stored at the output. From the simulation results, the conventional MPPT consumed a power of 324µW from the PV cell, which is higher than the 255µW consumed by this system. Therefore, the implementation of a power down system saved 21.2% more power than that of the conventional FOCV-based MPPT system. The size of the overall layout implemented in 65nm CMOS technology is 70.955 µm x 34.09 µm

    Solar Neutrinos Before and After KamLAND

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    We use the recently reported KamLAND measurements on oscillations of reactor anti-neutrinos, together with the data of previously reported solar neutrino experiments, to show that: (1) the total 8B neutrino flux emitted by the Sun is 1.00(1.0 \pm 0.06) of the standard solar model (BP00) predicted flux, (2) the KamLAND measurements reduce the area of the globally allowed oscillation regions that must be explored in model fitting by six orders of magnitude in the Delta m^2-tan^2 theta plane, (3) LMA is now the unique oscillation solution to a CL of 4.7sigma, (4) maximal mixing is disfavored at 3.1 sigma, (5) active-sterile admixtures are constrained to sin^2 eta<0.13 at 1 sigma, (6) the observed ^8B flux that is in the form of sterile neutrinos is 0.00^{+0.09}_{-0.00} (1 sigma), of the standard solar model (BP00) predicted flux, and (7) non-standard solar models that were invented to completely avoid solar neutrino oscillations are excluded by KamLAND plus solar at 7.9 sigma . We also refine quantitative predictions for future 7Be and p-p solar neutrino experiments.Comment: Published version, includes editorial improvement

    1-(Benzo[d]thiazol-2-yl)-3-phenylureas as dual inhibitors of casein kinase 1 and ABAD enzymes for treatment of neurodegenerative disorders

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    This work was supported by the Ministry of Health of the Czech Republic [no. NV15-28967 A], Specific Research Project of Faculty of Science, University of Hradec Kralove [no. 2103-2017], National Institute of Mental Health [NIMH CZ; no. ED2.1.00/03.0078] from the European Regional Development Fund, COST CA15135, The Alzheimer’s Society (specifically The Barcopel Foundation), The Rosetrees trust and The Biotechnology and Biological Sciences Research Council (BBSRC) [no. BB/J01446X/1]. Funding from Ministry of Economy and competitiveness, Spain [no. SAF2012-37979-C03-01] is also acknowledged.Several neurodegenerative disorders including Alzheimer’s disease (AD) have been connected with deregulation of casein kinase 1 (CK1) activity. Inhibition of CK1 therefore presents a potential therapeutic strategy against such pathologies. Recently, novel class of CK1-specific inhibitors with N-(benzo[d]thiazol-2-yl)-2-phenylacetamide structural scaffold has been discovered. 1-(benzo[d]thiazol-2-yl)-3-phenylureas, on the other hand, are known inhibitors amyloid-beta binding alcohol dehydrogenase (ABAD), an enzyme also involved in pathophysiology of AD. Based on their tight structural similarity, we decided to evaluate series of previously published benzothiazolylphenylureas, originally designed as ABAD inhibitors, for their inhibitory activity towards CK1. Several compounds were found to be submicromolar CK1 inhibitors. Moreover, two compounds were found to inhibit both, ABAD and CK1. Such dual-activity could be of advantage for AD treatment, as it would simultaneously target two distinct pathological processes involved in disease’s progression. Based on PAMPA testing both compounds were suggested to permeate the blood-brain barrier, which makes them, together with their unique dual activity, interesting lead compounds for further development.Publisher PDFPeer reviewe

    Real-world outcomes of sipuleucel-T treatment in PROCEED, a prospective registry of men with metastatic castration-resistant prostate cancer.

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    BackgroundThe large registry, PROVENGE Registry for the Observation, Collection, and Evaluation of Experience Data (PROCEED)(NCT01306890), evaluated sipuleucel-T immunotherapy for asymptomatic/minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC).MethodsPROCEED enrolled patients with mCRPC receiving 3 biweekly sipuleucel-T infusions. Assessments included overall survival (OS), serious adverse events (SAEs), cerebrovascular events (CVEs), and anticancer interventions (ACIs). Follow-up was for ≥3&nbsp;years or until death or study withdrawal.ResultsIn 2011-2017, 1976 patients were followed for 46.6&nbsp;months (median). The median age was 72&nbsp;years, and the baseline median prostate-specific antigen level was 15.0&nbsp;ng/mL; 86.7% were white, and 11.6% were African American. Among the patients, 1902 had 1 or more sipuleucel-T infusions. The median OS was 30.7&nbsp;months (95% confidence interval [CI], 28.6-32.2&nbsp;months). Known prognostic factors were independently associated with OS in a multivariable analysis. Among the 1255 patients who died, 964 (76.8%) died of prostate cancer (PC) progression. The median time from the first infusion to PC death was 42.7&nbsp;months (95% CI, 39.4-46.2&nbsp;months). The incidence of sipuleucel-T-related SAEs was 3.9%. The incidence of CVEs was 2.8%, and the rate per 100 person-years was 1.2 (95% CI, 0.9-1.6). The CVE incidence among 11,972 patients with mCRPC from the Surveillance, Epidemiology, and End Results-Medicare database was 2.8%; the rate per 100 person-years was 1.5 (95% CI, 1.4-1.7). One or more ACIs (abiraterone, enzalutamide, docetaxel, cabazitaxel, or radium 223) were received by 77.1% of the patients after sipuleucel-T; 32.5% and 17.4% of the patients experienced 1- and 2-year treatment-free intervals, respectively.ConclusionsPROCEED provides contemporary survival data for sipuleucel-T-treated men in a real-world setting of new life-prolonging agents, which will be useful in discussing treatment options with patients and in powering future trials with sipuleucel-T. The safety and tolerability of sipuleucel-T in PROCEED were consistent with previous findings

    Experimental demonstration of radicaloid character in a RuV=O intermediate in catalytic water oxidation

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    Water oxidation is the key half reaction in artificial photosynthesis. An absence of detailed mechanistic insight impedes design of new catalysts that are more reactive and more robust. A proposed paradigm leading to enhanced reactivity is the existence of oxyl radical intermediates capable of rapid water activation, but there is a dearth of experimental validation. Here, we show the radicaloid nature of an intermediate reactive toward formation of the O-O bond by assessing the spin density on the oxyl group by Electron Paramagnetic Resonance (EPR). In the study, an 17O-labeled form of a highly oxidized, short-lived intermediate in the catalytic cycle of the water oxidation catalyst cis,cis-[(2,2-bipyridine)2(H2O)RuIIIORuIII(OH2)(bpy)2]4+ was investigated. It contains Ru centers in oxidation states [4,5], has at least one RuV = O unit, and shows |Axx| = 60G 17O hyperfine splittings (hfs) consistent with the high spin density of a radicaloid. Destabilization of π-bonding in the d3 RuV = O fragment is responsible for the high spin density on the oxygen and its high reactivity

    Towards a sustainable approach to clustering small-scale farmers to market their agricultural produce

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    The University of the Philippines Mindanao and Curtin University have been organising small-scale vegetable farmers in Mindanao into cluster marketing groups to improve their access to markets and returns from the sale of their vegetable products using the 8-Step Clustering Approach for Agroenterprise Development developed by the Catholic Relief Services (Philippines). This paper reports on an action research investigation with around 30 marketing clusters. Cluster marketing has led to: better and wider market access, improved prices, reduced costs, improved human capital and social capital, and higher incomes. However, the current process may not lead to sustainable cluster marketing without support and may lead to dependency. This paper discusses strategies to overcome key challenges identified and deficiencies in the current process and suggests changes to the 8-step process so that it may improve the chances of cluster success and sustainability

    Assessing, quantifying and valuing the ecosystem services of coastal lagoons

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    The natural conservation of coastal lagoons is important not only for their ecological importance, but also because of the valuable ecosystem services they provide for human welfare and wellbeing. Coastal lagoons are shallow semi-enclosed systems that support important habitats such as wetlands, mangroves, salt-marshes and seagrass meadows, as well as a rich biodiversity. Coastal lagoons are also complex social-ecological systems with ecosystem services that provide livelihoods, wellbeing and welfare to humans. This study assessed, quantified and valued the ecosystem services of 32 coastal lagoons. The main findings of the study are: (i) the definitions of ecosystem services are still not generally accepted; (ii) the quantification of ecosystem services is made in many different ways, using different units; (iii) the evaluation in monetary terms of some ecosystem service is problematic, often relying on non-monetary evaluation methods; (iv) when ecosystem services are valued in monetary terms, this may represent very different human benefits; and, (v) different aspects of climate change, including increasing temperature, sea-level rise and changes in rainfall patterns threaten the valuable ecosystem services of coastal lagoons.DEVOTES project, from the European Union's Seventh Framework Programme for research, technological development and demonstration [308392]; networks and communities of Eurolag; Future Earth Coasts; SCOR; Fundacao para a Ciencia e a Tecnologia (FCT) Investigador Programme [IF/00331/2013]; Fundacao para a Ciencia e a Tecnologia [UID/MAR/04292/2013]; CESAM by FCT/MEC national funds (PIDDAC) [UID/AMB/50017/2013 - POCI-01-0145-FEDER-007638]; FEDER; European Commission, under the 7th Framework Programme through the collaborative research project LAGOONS [283157]; FCT [SFRH/BPD/107823/2015, SFRH/BPD/91494/2012
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