25 research outputs found

    Does outstretching the arms improve postural stability?

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    We spontaneously outstretch our arms when standing upon challenging surfaces, yet the effect of stretching the arms upon postural stability is unknown. We investigated whether stretching out the arms laterally improves postural control during tandem stance on a narrow beam. Twelve healthy participants stood upon a beam, right foot in front of the left foot, for 30 s with arms outstretched or down to the side, with eyes open and closed. Mediolateral head movement was characterised by Root Mean Square amplitude (RMS), sway path, velocity during the largest excursion and power spectrum. Spectra for lateral forces from a force platform beneath the beam were also recorded. Outstretching the arms significantly reduced RMS, sway path and velocity of maximum displacement of head movement with eyes closed but not with eyes open. A similar trend was present in the power spectra of head motion and sway platform lateral forces. In conclusion, outstretching the arms helps postural stability in challenging situations such as tandem stance on a narrow beam with eyes closed. Although the exact mechanisms require further investigation, the effects are most likely mediated by changes in segmental inertia and the ability to make corrective arm movements.MRC grant to A.M.B. (MC_U950770497

    A Self-Organized Energy Efficient Topology Control Protocol based on Cellular Learning Automata in Wireless Sensor Networks (SEETCLA)

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    Among some of sensor network properties which make it different from other networks, can refer to very high number of nodes, dynamic, and probably periodic topological changes and also some constraints in physical size of nodes, energy resource and power of processing. According to these restrictions, giving solutions and self-configurable protocols that do global tasks without requiring a central controller or manager are necessary. Topology control and node scheduling that constitute a part of the maintenance phase of self-organization protocols, are providing the main goal of this phase which is increasing network lifetime and also maintaining the infrastructure support for the network. In consideration of learning Automata’s abilities such as low computational load, the ability of being used in distributed environments, with no precise information, the adaptability to changes via lo

    Synthesis, radiolabelling, and biological assessment of folic acid-conjugated G-3 99mTcdendrimer as the breast cancer molecular imaging agent

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    Hence, in this study, the authors aimed to develop a dendrimer-based imaging agent comprised of poly(ethylene glycol) (PEG)-citrate, technetium-99 m (99mTc), and folic acid. The dendrimer-G3 was synthesised and conjugated with folic acid, which confirmed by Fourier transform infrared, proton nuclear magnetic resonance, dynamic light scattering, and transition electron microscopy. 2, 3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-Tetrazolium-5-Carboxanilide cytotoxicity assay kit was used to measure the cellular toxicity of dendrimer. Imaging and biodistribution studies were conducted on the mice bearing tumour. The results showed that the fabricated dendrimer-G3 has a size of 90 ± 3 nm, which was increased to 100 ± 4 nm following the conjugation with folic acid. The radiostablity investigation showed that the fabricated dendrimers were stable in the human serum at various times. Toxicity assessment confirmed no cellular toxicity against HEK-293 cells at 0.25, 0.5, 1, 2, 4, and 8 mg/ μl concentrations. The in vivo studies demonstrated that the synthesised dendrimers were able to provide a bright SPECT image applicable for tumour detection. In conclusion, the authors' study documented the positive aspects of PEG-citrate dendrimer conjugated with folic acid as the SPECT contrast agent for breast cancer detection. © The Institution of Engineering and Technology 2020

    Evaluation of prognostic factors associated with differentiated thyroid carcinoma with pulmonary metastasis

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    Background: Because one of the major sites for metastasis of thyroid cancers is the lung, studying the pattern of pulmonary metastasis may provide useful information for the effective treatment of these patients. In this study, by assessing the metastasis pattern, we aimed to identify the factors thatmay affect prognosis and response to treatment in patientswith differentiated thyroid carcinoma (DTC) with pulmonary metastasis. Methods: This retrospective study included 75 patients with DTC with pulmonary metastasis whowere referred to our nuclear medicine section over a period of 10 years. The data obtained were analyzed with regard to response to treatment to assess the effects of the included factors on prognosis. Results: Of the 1746 patients referred to our section, 75 (4.3%) had pulmonary metastasis. According to the pattern of pulmonary metastasis, they were divided into 4 groups: nodular, diffuse, combined, and other. The mean age of the patients was 43.8 ± 18.5 years. After the follow-up, 58 patients survived, 14 of whom responded to the treatment. The mean number of radioiodine therapy sessions that the patients received was 3.2 ± 2, and the mean cumulative dose was 554.7 ± 387.8 mCi. Statistical analysis of the data revealed that there was no significant difference in the response to treatment between patients with different patterns of pulmonary metastasis (P > 0.3). However, significant differences were reported in the response to treatment between patients with papillary thyroid carcinoma and those with follicular thyroid carcinoma (P < 0.03). The 1-, 5-, and 9-year survival rates were reported as 98%, 76%, and 51%, respectively. Conclusions: Patients with DTC with pulmonary metastasis have a relatively favorable prognosis and response rate, as well as longer survival. The type of DTC is the only factor that affects the response to treatment. © 2016 Wolters Kluwer Health, Inc. All rights reserved

    Phase formation, crystal structures and magnetic properties of perovskite-type phases in the system La2Co1+z(MgxTi1-x)1-zO6

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    Perovskite-type cobaltates in the system La(2)Co(1+z) (Mg(x)Ti(1-x))(1-z)O(6) were studied for z=0 &lt;= x &lt;= 0.6 and 0 &lt;= x &lt;= 0.9, using X-ray and neutron powder diffraction, electron diffraction (ED), magnetic susceptibility measurements and X-ray absorption near-edge structure (XANES) spectroscopy. The samples were synthesised using the citrate route in air at 1350 degrees C. The space group symmetry of the structure changes from P2(1)/n via Pbnm to R (3) over barc with both increasing Mg content and increasing Co content. The La(2)Co(Mg(x)Ti(1-x))O(6) (z=0) compounds show anti-ferromagnetic couplings of the magnetic moments for the Co below 15 K for x=0, 0.1 and 0.2. XANES spectra show for the compositions 0 &lt;= x &lt;= 0.5 a linear decrease in the L(3)/(L(3)+ L(2))Co-L(2.3) edge branching ratio with x, in agreement with a decrease of the average Co ion spin-state, from a high-spin to a lower-spin-state, with decreasing nominal Co(2+) ion content.Studier av koboltbaserade perovskiter för användning i bränslecelle

    Synthesis and characterization of perovskite-type SrxY1−xFeO3−δ (0.63≤x&lt;1.0) and Sr0.75Y0.25Fe1−yMyO3−δ (M=Cr, Mn, Ni), (y=0.2, 0.33, 0.5)

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    Oxygen-deficient ferrates with the cubic perovskite structure SrxY1-xFeO3-d were prepared in air (0.71 ≤ x ≤ 0.91) as well as in N2 (x=0.75 and 0.79) at 1573K. The oxygen content of the compounds prepared in air increases with increasing strontium content from 3-δ=2.79(2) for x=0.75 to 3-δ=2.83(2) for x=0.91. Refinement of the crystal structure of Sr0.75Y0.25FeO2.79 using TOF neutron powder diffraction (NPD) data shows high anisotropic atomic displacement parameter (ADP) for the oxygen atom resulting from a substantial cation and anion disorder. Electron diffraction (ED) and high-resolution electron microscopy (HREM) studies of Sr0.75Y0.25FeO2.79 reveal a modulation along &lt;100&gt;p with G± ~0.4&lt;100&gt;p indicating a local ordering of oxygen vacancies. Magnetic susceptibility measurements at 5-390K show spin-glass behaviour with dominating antiferromagnetic coupling between the magnetic moments of Fe cations. Among the studied compositions, Sr0.75Y0.25FeO2.79 shows the lowest thermal expansion coefficient (TEC) of 10.5 ppm K-1 in air at 298-673K. At 773-1173K TEC increases up to 17.2 ppm K-1 due to substantial reduction of oxygen content. The latter also results in a dramatic decrease of the electrical conductivity in air above 673K. Partial substitution of Fe by Cr, Mn and Ni according to the formula Sr0.75Y0.25Fe1-yMyO3-δ (y=0.2, 0.33, 0.5) leads to cubic perovskites for all substituents with y=0.2. Their TECs are higher in comparison with un-doped Sr0.75Y0.25FeO2.79. Only M=Ni has increased electrical conductivity compared to un-doped Sr0.75Y0.25FeO2.79.Studies of cobalt based perovskites for cathode materials in solid oxide fuel cells

    An Exploratory Study of Units of Reporting Opium Usein Iran: Implications for Epidemiologic Studies

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    BACKGROUND: Measuring the amount of opium use is a challenge in epidemiologic studies. Self-report of amount of opium use at each consumption, widely used in the literature, usually fails to provide a good estimate. The purpose of this study is to systematically study the perceived weight units of reported opium use in Iran, and compare them to the standardized units of weight measurement. METHODS: An exploratory descriptive study was conducted in six major cities of Iran. Study participants were interviewed and asked to use a Play-Doh-like material to demonstrate the amount of opium they use. To obtain an estimate of the weight of the material used, we multiplied the volume by the density of the opium product. We experimentally determined the density of the commonly used opium products. We used medians and inter-quartile ranges (IQRs) to report the typical amount of each unit. RESULTS: A total of 108 individuals participated in this study. The most frequently reported unit was "gram"; the median perceived weight for one gram (g) of opium was 0.24 (IQR: 0.16) g. The second most commonly used unit was nokhod with a median of 0.16 (IQR: 0.16) g, followed by mesghaal and hab/habeh, which were 1.28 (IQR: 0.81) and 0.16 (IQR: 0.16) g, respectively. The median perceived weight of mesghaal and gram in the studied cities was less than the expected standardized values. CONCLUSION: In conclusion, the reported amount of opium use is highly inaccurate and unreliable, and is mainly subject to underestimation. © 2019 The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
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