533 research outputs found

    Measurement of collagen synthesis by cells grown under different mechanical stimuli

    Get PDF
    INTRODUCTION: The use of scaffolds in tissue engineering is essential to provide cells with a matrix for cell proliferation and differentiation resulting in tissue regeneration. Normally this process involves seeding cells onto an artificial biodegradable scaffold providing mechanical support for cells until there is sufficient extracellular matrix deposition (ECM) to replace the artificial scaffold. Collagen is the bulk protein found in the ECM and measurement of its synthesis is the most direct, absolute indicator of ECM production

    The correlation of length and weight of Kutum (Rutilus frisii kutum) in the central south of Caspian Sea with copper and zinc concentration in muscle and liver tissues

    Get PDF
    Concentration of copper (Cu) and zinc (Zn) in liver and muscle tissues of Kutum (Rutilus frisii kutum) of the Caspian Sea was assessed to study possible correlation of length and weight and the bioaccumulation of these heavy metals in the fish. Concentration of the metals in liver was higher than muscle (Zn: 55.2, Cu: 41.5 kg/g) while the concentrations in the muscle tissue were lower than permissible limits proposed by FAO. Significant correlations were not detected between mean Zn and cu concentration and fish size. Finally, no significant difference was found in the concentration of the heavy metals in male and female fish specimens (P>0.05)

    Subarachnoid haemorrhage secondary to traumatic intracranial aneurysm of the posterior cerebral circulation: case series and literature review

    Get PDF
    Background To identify the clinical features, rebleed risk, timing and method of diagnosis, complications and outcome for subarachnoid haemorrhage (SAH) from traumatic intracranial aneurysm (TICA) of the posterior circulation. Subjects included 26 patients aged 3–54 (mean 24.8). Methods Case series and literature search to identify all reported cases. Results In our series, two of three cases were fatal as a result of rebleed, and one case had a good outcome with no deficit, following prompt diagnosis and embolisation. Our key findings from the literature review were: 30.7 % of patients were age 16 and under; 88 % had an acute drop in consciousness, 46 % in a delayed manner; the mean time to diagnosis was 7.5 days; initial cerebrovascular imaging was normal in 23 %; the rebleed rate was 23 %; 61 % required emergency diversion of cerebrospinal fluid; 11 % developed vasospasm requiring treatment; 19.2 % had deficits that rendered them unable to live independently. The mortality rate was 27 %. Conclusions SAH from ruptured posterior circulation TICA is associated with significant morbidity and mortality. A high index of suspicion as well as prompt diagnosis, repeat imaging in selected cases, and treatment of any associated TICA can be crucial to a favourable outcome

    Des modèles biologiques à l'amélioration des plantes

    Get PDF

    A New High-intensity, Low-momentum Muon Beam for the Generation of Low-energy Muons at PSI

    Get PDF
    At the Paul Scherrer Institute (PSI, Villigen, Switzerland) a new high-intensity muon beam line with momentum p < 40MeV/c is currently being commissioned. The beam line is especially designed to serve the needs of the low-energy, polarized positive muon source (LE-μ+) and LE-μ SR spectrometer at PSI. The beam line replaces the existing μ E4 muon decay channel. A large acceptance is accomplished by installing two solenoidal magnetic lenses close to the muon production target E that is hit by the 590-MeV PSI proton beam. The muons are then transported by standard large aperture quadrupoles and bending magnets to the experiment. Several slit systems and an electrostatic separator allow the control of beam shape, momentum spread, and to reduce the background due to beam positrons or electrons. Particle intensities of up to 3.5 × 108 μ+/s and 107 μ−/s are expected at 28MeV/c beam momentum and 1.8mA proton beam current. This will translate into a LE-μ+ rate of 7,000/s being available at the LE-μ SR spectrometer, thus achieving μ+ fluxes, that are comparable to standard μ SR facilitie

    Understanding the saturation power of Josephson Parametric Amplifiers made from SQUIDs arrays

    Full text link
    We report on the implementation and detailed modelling of a Josephson Parametric Amplifier (JPA) made from an array of eighty Superconducting QUantum Interference Devices (SQUIDs), forming a non-linear quarter-wave resonator. This device was fabricated using a very simple single step fabrication process. It shows a large bandwidth (45 MHz), an operating frequency tunable between 5.9 GHz and 6.8 GHz and a large input saturation power (-117 dBm) when biased to obtain 20 dB of gain. Despite the length of the SQUID array being comparable to the wavelength, we present a model based on an effective non-linear LC series resonator that quantitatively describes these figures of merit without fitting parameters. Our work illustrates the advantage of using array-based JPA since a single-SQUID device showing the same bandwidth and resonant frequency would display a saturation power 15 dB lower.Comment: 12 pages, 9 figures, Appendices include

    Growth, photosynthesis and biomass allocation of different kenaf (Hibiscus cannabinus L.,) accessions grown on sandy soil.

    Get PDF
    Growth, photosynthesis, and biomass allocation of kenaf accessions were investigated. Forty kenaf accessions from tropical and subtropical regions of the world were grown on marginal sandy soil in a field at Kelantan to determine differences in their growth, photosynthesis and biomass allocation. The experiment was arranged using three replicates in a randomized complete block design. Basal diameter, plant height, leaf number, leaf area and photosynthesis were measured, these being the determinants of growth and biomass production. Plant roots, stems and leaves were separated and biomass content determined at harvest. Accession 35 had the highest value for basal diameter (17.44 mm), plant height (251.73 cm), leaf quantity (81.55), leaf area (1455.62 cm2 plant-1) and photosynthesis (16.92 µmol m-2s-1), followed by accession 28. A positive relationship was noticed between plant height, leaf area, photosynthesis, biomass production, root mass and leaf area. Total biomass for the different kenaf accessions ranged from 26.26 to 93.06 g plant-1 (-1 needs to be superscripted). Stems accounted for the greatest proportion of dry mass (67.05%), followed by roots(21.15%). Dry mass accumulation in the stem was highest in accession 35, followed by accession 28. Using cluster analysis, the accessions were divided into two major groups, in which accessions 35 and 28 from the first group had the highest values of all measured parameters. The results of the study will aid in the selection of better accessions for growers to produce kenaf that is best suited to marginal sandy soil

    Fast high fidelity quantum non-demolition qubit readout via a non-perturbative cross-Kerr coupling

    Full text link
    Qubit readout is an indispensable element of any quantum information processor. In this work, we experimentally demonstrate a non-perturbative cross-Kerr coupling between a transmon and a polariton mode which enables an improved quantum non-demolition (QND) readout for superconducting qubits. The new mechanism uses the same experimental techniques as the standard QND qubit readout in the dispersive approximation, but due to its non-perturbative nature, it maximizes the speed, the single-shot fidelity and the QND properties of the readout. In addition, it minimizes the effect of unwanted decay channels such as the Purcell effect. We observed a single-shot readout fidelity of 97.4% for short 50 ns pulses, and we quantified a QND-ness of 99% for long measurement pulses with repeated single-shot readouts

    Community women's lifestyle and eating disorders in the era of COVID-19 pandemic : a 15-year follow-up study

    Get PDF
    Most studies suggest that COVID-19 has adversely affected the quality of life and mental health, including eating disorders. However, studies have yet to examine longitudinally the impact of COVID-19 on eating disorder symptomatic individuals. This study aims to examine longitudinally the impact of the COVID-19 pandemic on the lifestyle and eating disorder symptoms of a symptomatic group of community-dwelling women. These women (n = 171) were enrolled in a longitudinal study, completed a COVID-19 modular self-report (post or Qualtrics, 2020/21), and participated in the current study. This study examined a 15th year follow-up. In 2020, 40% were tested for COVID-19. Of these, 87% had negative results; 5.3% self-isolated at home; 20.5% stopped working/studying in person; 28% continued online work/study; and 28% stopped work/studying in person. The pandemic affected sporting activities, music, and club activities (32.7% discontinued); 38% socialized in person; 16% socialized online; and 10% completely stopped socializing. Preliminary findings showed that the respondents showed no significant changes in levels of psychological distress (K10: 21.4 ± 9.8 vs. 19.0 ± 7.1, p < 0.171), and impaired quality of life (SF12: 50.9 ± 8.0 vs. 48.3 ± 9.5, p < 0.055) at 15-year follow-up. Eating disorder symptoms increased over time (EDE-Q global: 2.1 ± 1.4 vs. 2.9 ± 1.4, p < 0.013). Observed worsening of eating disorder-related symptoms during the COVID-19 pandemic may be due to interrupted eating patterns, exercise restrictions and the absence of social support. Provision and access to interventions to support those affected by eating disorders are a high priority, especially during these times. Further analyses with data imputation may find or further establish direct implications of COVID-19 in eating disorders
    corecore