4,031 research outputs found

    Static characterization of the driving, normal and stall forces of a double-sided moving-permanent magnet-type planar actuator based on orthogonal planar windings

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    © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This work presents a study of the traction, normal and stall forces in a two-sided planar actuator with orthogonal planar windings and a mover that comprises two cars magnetically coupled to each other through two pairs of permanent magnets (PMs). There is no ferromagnetic armature core because of the permanent magnets array in the mover and orthogonal traction forces can be generated in order to move both cars jointly in any direction on a plane. The stall force is the minimal force necessary to break up the magnetic coupling between the two cars. When one of the cars is subjected to an external force through the x-or y-axis, the cars can become out of alignment with respect to each other and the planar actuator cannot work properly. The behavior of the forces was modelled by numerical and analytical methods and experimental results were obtained from tests carried out on a prototype. The average sensitivity of the measured static propulsion planar force along either axis is 4.48 N/A. With a 20-mm displacement between the cars along the direction of the x-axis and no armature current, a magnetic stall force of 17.26 N is produced through the same axis in order to restore the alignment of the two cars

    Zika virus preferentially replicates in the female reproductive tract after vaginal inoculation of rhesus macaques.

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    Zika virus (ZIKV) is a mosquito-transmitted virus that can cause severe defects in an infected fetus. ZIKV is also transmitted by sexual contact, although the relative importance of sexual transmission is unclear. To better understand the role of sexual transmission in ZIKV pathogenesis, a nonhuman primate (NHP) model of vaginal transmission was developed. ZIKV was readily transmitted to mature cycling female rhesus macaque (RM) by vaginal inoculation with 104-106 plaque-forming units (PFU). However, there was variability in susceptibility between the individual RM with 1->8 vaginal inoculations required to establish infection. After treatment with Depoprovera, a widely used contraceptive progestin, two RM that initially resisted 8 vaginal ZIKV inoculations became infected after one ZIKV inoculation. Thus, Depoprovera seemed to enhance susceptibility to vaginal ZIKV transmission. Unexpectedly, the kinetics of virus replication and dissemination after intravaginal ZIKV inoculation were markedly different from RM infected with ZIKV by subcutaneous (SQ) virus inoculation. Several groups have reported that after SQ ZIKV inoculation vRNA is rapidly detected in blood plasma with vRNA less common in urine and saliva and only rarely detected in female reproductive tract (FRT) secretions. In contrast, in vaginally inoculated RM, plasma vRNA is delayed for several days and ZIKV replication in, and vRNA shedding from, the FRT was found in all 6 animals. Further, after intravaginal transmission ZIKV RNA shedding from FRT secretions was detected before or simultaneously with plasma vRNA, and persisted for at least as long. Thus, ZIKV replication in the FRT was independent of, and often preceded virus replication in the tissues contributing to plasma vRNA. These results support the conclusion that ZIKV preferentially replicates in the FRT after vaginal transmission, but not after SQ transmission, and raise the possibility that there is enhanced fetal infection and pathology after vaginal ZIKV transmission compared to a mosquito transmitted ZIKV

    The Private Higgs

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    We introduce Higgs democracy in the Yukawa sector by constructing a model with a private Higgs and a dark scalar for each fermion thus addressing the large hierarchy among fermion masses. The model has interesting implications for the LHC, while the Standard Model phenomenology is recovered at low energies. We discuss some phenomenological implications such as FCNC, new Higgses at the TeV scale and dark matter candidates.Comment: 8 pages, no figures. Version published in Phys. Lett.

    Termómetros Clínicos

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    Na prática clínica, várias decisões relacionadas com o diagnóstico e tratamento resultam da análise dos valores da temperatura corporal, sendo a medição deste parâmetro habitualmente realizada com instrumentos de medição, designados por termómetros clínicos. A correta medição da temperatura corporal assume relevância na prática diária dos cuidados de saúde, sendo um parâmetro regularmente avaliado no diagnóstico e monitorização do estado de saúde de um indivíduo.info:eu-repo/semantics/publishedVersio

    The peculiar velocity field in a quintessence model

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    We investigate the evolution of matter density perturbations and some properties of the peculiar velocity field for a special class of exponential potentials in a scalar field model for quintessence, for which a general exact solution is known. The data from the 2-degree Field Galaxy Redshift Survey (2dFGRS) suggest a value of the today pressureless matter density Omega_M0 = 0.18 +- 0.05.Comment: 11 pages, 3 figure

    Cosmological Imprint of an Energy Component with General Equation of State

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    We examine the possibility that a significant component of the energy density of the universe has an equation-of-state different from that of matter, radiation or cosmological constant (Λ\Lambda). An example is a cosmic scalar field evolving in a potential, but our treatment is more general. Including this component alters cosmic evolution in a way that fits current observations well. Unlike Λ\Lambda, it evolves dynamically and develops fluctuations, leaving a distinctive imprint on the microwave background anisotropy and mass power spectrum.Comment: revised version, with added references, to appear in Phys. Rev. Lett. (4 pages Latex, 2 postscript figures

    Instrumentos de Medição da Pressão Arterial

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    No setor da saúde, as medições e os instrumentos de medição desempenham um papel fundamental no quotidiano dos cidadãos. Variadíssimas decisões clínicas são fundamentadas por resultados de medições, e suportadas na evidência dos mesmos. Por razões de diversa índole, os resultados obtidos a partir de sistemas de medição podem apresentar variabilidade que conduzem a erros de diagnóstico e de tratamento, comprometendo o rigor da medição e os recursos disponíveis. Neste contexto, o presente trabalho tem como finalidade divulgar conceitos gerais e específicos, aplicados a instrumentos e sistemas de medição, apresentando-se como um documento de consulta e um guia para a implementação de boas práticas no âmbito da Metrologia na Saúde.info:eu-repo/semantics/publishedVersio

    Non-invasive grading of astrocytic tumours from the relative contents of myo-inositol and glycine measured by in vivo MRS

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    Altres ajuts: INTERPRET (EU-IST1999-10310). This work was also partially funded by the Centro de Investigación Biomédica en Red - Bioingeniería, Biomateriales y Nanomedicina, which is an initiative of the Instituto de Salud Carlos III (Spain) co-funded by EU FEDER funds.MRI and MRS are established methodologies for evaluating intracranial lesions. One MR spectral feature suggested for in vivo grading of astrocytic tumours is the apparent myo-Inositol (mI) intensity (ca 3.55ppm) at short echo times, although glycine (gly) may also contribute in vivo to this resonance. The purpose of this study was to quantitatively evaluate the mI + gly contribution to the recorded spectral pattern in vivo and correlate it with in vitro data obtained from perchloric acid extraction of tumour biopsies. Patient spectra (n = 95) at 1.5T at short (20-31 ms) and long (135-136 ms) echo times were obtained from the INTERPRET MRS database (http://gabrmn.uab.es/interpretvalidateddb/). Phantom spectra were acquired with a comparable protocol. Spectra were automatically processed and the ratios of the (mI + gly) to Cr peak heights ((mI + gly)/Cr) calculated. Perchloric acid extracts of brain tumour biopsies were analysed by high-resolution NMR at 9.4T. The ratio (mI + gly)/Cr decreased significantly with astrocytic grade in vivo between low-grade astrocytoma (A2) and glioblastoma multiforme (GBM). In vitro results displayed a somewhat different tendency, with anaplastic astrocytomas having significantly higher (mI + gly)/Cr than A2 and GBM. The discrepancy between in vivo and in vitro data suggests that the NMR visibility of glycine in glial brain tumours is restricted in vivo

    Gender-dependent differences in plasma matrix metalloproteinase-8 elevated in pulmonary tuberculosis.

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    Tuberculosis (TB) remains a global health pandemic and greater understanding of underlying pathogenesis is required to develop novel therapeutic and diagnostic approaches. Matrix metalloproteinases (MMPs) are emerging as key effectors of tissue destruction in TB but have not been comprehensively studied in plasma, nor have gender differences been investigated. We measured the plasma concentrations of MMPs in a carefully characterised, prospectively recruited clinical cohort of 380 individuals. The collagenases, MMP-1 and MMP-8, were elevated in plasma of patients with pulmonary TB relative to healthy controls, and MMP-7 (matrilysin) and MMP-9 (gelatinase B) were also increased. MMP-8 was TB-specific (p<0.001), not being elevated in symptomatic controls (symptoms suspicious of TB but active disease excluded). Plasma MMP-8 concentrations inversely correlated with body mass index. Plasma MMP-8 concentration was 1.51-fold higher in males than females with TB (p<0.05) and this difference was not due to greater disease severity in men. Gender-specific analysis of MMPs demonstrated consistent increase in MMP-1 and -8 in TB, but MMP-8 was a better discriminator for TB in men. Plasma collagenases are elevated in pulmonary TB and differ between men and women. Gender must be considered in investigation of TB immunopathology and development of novel diagnostic markers
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