780 research outputs found

    Wavelets: a powerful tool for studying rotation, activity, and pulsation in Kepler and CoRoT stellar light curves

    Full text link
    Aims. The wavelet transform has been used as a powerful tool for treating several problems in astrophysics. In this work, we show that the time-frequency analysis of stellar light curves using the wavelet transform is a practical tool for identifying rotation, magnetic activity, and pulsation signatures. We present the wavelet spectral composition and multiscale variations of the time series for four classes of stars: targets dominated by magnetic activity, stars with transiting planets, those with binary transits, and pulsating stars. Methods. We applied the Morlet wavelet (6th order), which offers high time and frequency resolution. By applying the wavelet transform to the signal, we obtain the wavelet local and global power spectra. The first is interpreted as energy distribution of the signal in time-frequency space, and the second is obtained by time integration of the local map. Results. Since the wavelet transform is a useful mathematical tool for nonstationary signals, this technique applied to Kepler and CoRoT light curves allows us to clearly identify particular signatures for different phenomena. In particular, patterns were identified for the temporal evolution of the rotation period and other periodicity due to active regions affecting these light curves. In addition, a beat-pattern signature in the local wavelet map of pulsating stars over the entire time span was also detected.Comment: Accepted for publication on A&

    Fabrication of a Horizontal and a Vertical Large Surface Area Nanogap Electrochemical Sensor

    Get PDF
    Nanogap sensors have a wide range of applications as they can provide accurate direct detection of biomolecules through impedimetric or amperometric signals. Signal response from nanogap sensors is dependent on both the electrode spacing and surface area. However, creating large surface area nanogap sensors presents several challenges during fabrication. We show two different approaches to achieve both horizontal and vertical coplanar nanogap geometries. In the first method we use electron-beam lithography (EBL) to pattern an 11 mm long serpentine nanogap (215 nm) between two electrodes. For the second method we use inductively-coupled plasma (ICP) reactive ion etching (RIE) to create a channel in a silicon substrate, optically pattern a buried 1.0 mm × 1.5 mm electrode before anodically bonding a second identical electrode, patterned on glass, directly above. The devices have a wide range of applicability in different sensing techniques with the large area nanogaps presenting advantages over other devices of the same family. As a case study we explore the detection of peptide nucleic acid (PNA)−DNA binding events using dielectric spectroscopy with the horizontal coplanar device

    BLINDED VS ULTRASOUND-GUIDED CORTICOSTEROID INJECTIONS for the TREATMENT of the GREATER TROCHANTERIC PAIN SYNDROME (SDPT): A RANDOMIZED CONTROLLED TRIAL

    Get PDF
    Universidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilWeb of Scienc

    Toxicidade do óleo de Piper aduncum L. a adultos de Cerotoma tingomarianus Bechyné (Coleoptera: Chrysomelidae).

    Get PDF
    No óleo essencial de Piper aduncum L. (Piperaceae) predomina o fenilpropanóide dilapiol, com reconhecida ação inseticida e sinergista. A abundância dessa piperácea no Acre e a necessidade do controle de Cerotoma tingomarianus Bechyné estimularam a realização desta pesquisa com o objetivo de avaliar a toxicidade do óleo essencial de P. aduncum sobre adultos da praga. Avaliou-se o efeito da aplicação de contato tópica (DL50 e TL50) e da ação por contato com superfície contaminada (papel-filtro) (CL50 ) de diferentes concentrações do óleo, por meio da mortalidade e consumo foliar do inseto. Verificou-se que a toxicidade do óleo de P. aduncum para C. tingomarianus foi alta, considerando-se a CL50 = 0,06 ml de óleo/ cm2 e DL50 = 0,002 ml de óleo/ mg de inseto. A mortalidade dos insetos alcançou praticamente 100% nas concentrações de 1% do óleo na avaliação por contato (papel-filtro) e de 5% a 30% nas concentrações aplicadas topicamente. Houve redução significativa do consumo foliar dos insetos nas concentrações de 2,5% e 5%, além da redução do TL50 em função do aumento das concentrações. O óleo de P. aduncum apresenta efeito inseticida para C. tingomarianus na concentração de 0,04% por contato (papel-filtro), provocando ainda distúrbios fisiológicos pela ação da aplicação tópica em concentrações superiores a 2,5%

    Atividade inseticida do óleo essencial de Tanaecium nocturnum (Barb. Rodr.) Bur. & K. Shum (Bignoneaceae) sobre Sitophilus zeamais Motsch. (Coleoptera: Curculionidae).

    Get PDF
    O óleo essencial extraído de folhas frescas de Tanaecium nocturnum (Barb. Rodr.) Bur.& K. Shum por destilação de arraste a vapor foi avaliado quanto à toxicidade a Sitophilus zeamais Motsch., principal praga do milho armazenado. Papel de filtro e grãos de milho foram impregnados pelo óleo para se avaliar o efeito por via de contato (papel-filtro) e fumigação, respectivamente. Para avaliação do efeito da aplicação tópica 0,5 µl das diferentes concentrações do óleo foram aplicadas em adultos do inseto. A partir de uma ampla faixa de concentrações, foram determinadas as mais promissoras para os bioensaios definitivos. Na determinação das dose/concentrações-letais (DL50 e CL50) foi utilizada a análise de Probit, realizando-se também, uma análise de regressão linear conjunta de todos os dados de mortalidade. O óleo de T. nocturnum foi considerado tóxico para S. zeamais baseado nos seguintes valores: CL50 de 14,1 ng.cm-2 e CL50 de 1.321,6 ng.g-1 de grãos para os efeitos de contacto (papel-filtro) e fumigação, respectivamente, e DL50 de 14,7 µg.mg-1 de inseto para efeito tópico. Porcentagens de mortalidade próximas a 100 % foram obtidas nas concentrações de: 2 e 5 % (m/v) (contato), 3 4, e 5 % (m/v) (fumigação) e 10 % (m/v) para o efeito de aplicação tópica. O presente estudo mostrou que o ácido cianídrico, liberado do óleo essencial de T. nocturnum por hidrólise, pode ter atividade inseticida para S. zeamais e que concentrações acima de 4 % (m/v) são promissoras no controle do inseto

    3D-Printed Hollow Microneedle-Lateral Flow Devices for Rapid Blood-Free Detection of C-Reactive Protein and Procalcitonin

    Get PDF
    Hollow microneedle devices as a technology for interstitial fluid extraction show promise for the minimally invasive point-of-care detection of analytes. Despite increasing efforts toward on-patch diagnostics, the use of hollow microneedles has been limited due to the complexity caused by integrating hollow microneedles with established point-of-care diagnostic techniques. Herein, a 3D printing method is utilized, to provide low-cost manufacturing of custom-designed hollow microneedle devices, allowing for easy integration with lateral flow assays for rapid and blood-free diagnostics. Microneedle surface modification through PEGylation results in prolonged and enhanced hydrophilicity, enabling passive uptake of small volume samples (≈22.5 µL) and an enhanced shelf life. The hollow microneedle devices are deemed non-cytotoxic to cell types found within the skin following short-term and prolonged exposure in accordance with ISO10993. Furthermore, the devices demonstrate high mechanical strength and successfully penetrate porcine skin grafts without damaging the surrounding skin morphology. This work also demonstrates for the first time the use of hollow microneedles for the simultaneous detection, at clinically relevant concentrations, of C-reactive protein (LoD = 10 µg mL−1) and procalcitonin (LoD = 1 ng mL−1), through porcine skin, ultimately demonstrating the beneficial use of manufactured 3D-printed hollow microneedles towards low-cost blood-free diagnostics of inflammation markers

    Current Results of the EC-sponsored Catchment Modelling (CatchMod) Cluster

    Get PDF
    To support the Water Framework Directive implementation, much research has been commissioned at both national and European levels. CatchMod is a cluster of these projects, which is focusing on the development of computational catchment models and related tools. This paper presents an overview of the results of the CatchMod cluster to dat

    3D-Printed Hollow Microneedle-Lateral Flow Devices for Rapid Blood-Free Detection of C-Reactive Protein and Procalcitonin

    Get PDF
    Hollow microneedle devices as a technology for interstitial fluid extraction show promise for the minimally invasive point-of-care detection of analytes. Despite increasing efforts toward on-patch diagnostics, the use of hollow microneedles has been limited due to the complexity caused by integrating hollow microneedles with established point-of-care diagnostic techniques. Herein, a 3D printing method is utilized, to provide low-cost manufacturing of custom-designed hollow microneedle devices, allowing for easy integration with lateral flow assays for rapid and blood-free diagnostics. Microneedle surface modification through PEGylation results in prolonged and enhanced hydrophilicity, enabling passive uptake of small volume samples (≈22.5 µL) and an enhanced shelf life. The hollow microneedle devices are deemed non-cytotoxic to cell types found within the skin following short-term and prolonged exposure in accordance with ISO10993. Furthermore, the devices demonstrate high mechanical strength and successfully penetrate porcine skin grafts without damaging the surrounding skin morphology. This work also demonstrates for the first time the use of hollow microneedles for the simultaneous detection, at clinically relevant concentrations, of C-reactive protein (LoD = 10 µg mL−1) and procalcitonin (LoD = 1 ng mL−1), through porcine skin, ultimately demonstrating the beneficial use of manufactured 3D-printed hollow microneedles towards low-cost blood-free diagnostics of inflammation markers
    corecore