27,550 research outputs found

    The associations of adipokines with selected markers of the renin-angiotensinogen-aldosterone system: the multi-ethnic study of atherosclerosis.

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    Among obese individuals, increased sympathetic nervous system (SNS) activity results in increased renin and aldosterone production, as well as renal tubular sodium reabsorption. This study determined the associations between adipokines and selected measures of the renin-angiotensinogen-aldosterone system (RAAS). The sample consisted of 1970 men and women from the Multi-Ethnic Study of Atherosclerosis who were free of clinical cardiovascular disease at baseline and had blood assayed for adiponectin, leptin, plasma renin activity (PRA) and aldosterone. The mean age was 64.7 years and 50% were female. The mean (s.d.) PRA and aldosterone were 1.45 (0.56) ng ml(-1) and 150.1 (130.5) pg ml(-1), respectively. After multivariable adjustment, a 1-s.d. increment of leptin was associated with a 0.55 ng ml(-1) higher PRA and 8.4 pg ml(-1) higher aldosterone (P<0.01 for both). Although adiponectin was not significantly associated with PRA levels, the same increment in this adipokine was associated with lower aldosterone levels (-5.5 pg ml(-1), P=0.01). Notably, the associations between aldosterone and both leptin and adiponectin were not materially changed with additional adjustment for PRA. Exclusion of those taking antihypertensive medications modestly attenuated the associations. The associations between leptin and both PRA and aldosterone were not different by gender but were significantly stronger among non-Hispanic Whites and Chinese Americans than African and Hispanic Americans (P<0.01). The findings suggest that both adiponectin and leptin may be relevant to blood pressure regulation via the RAAS, in that the associations appear to be robust to antihypertension medication use and that the associations are likely different by ethnicity

    Upper bounds for the eigenvalues of Hessian equations

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    We prove some upper bounds for the Dirichlet eigenvalues of a class of fully nonlinear elliptic equations, namely the Hessian equationsComment: 15 pages, 1 figur

    MHD convective heat transfer of nanofluids through a flexible tube with buoyancy : a study of nano-particle shape effects

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    This paper presents an analytical study of magnetohydrodynamics and convective heat transfer of nanofluids synthesized by three different shaped (brick, platelet and cylinder) silver (Ag) nanoparticles in water. A two-phase nanoscale formulation is adopted which is more appropriate for biophysical systems. The flow is induced by metachronal beating of cilia and the flow geometry is considered as a cylindrical tube. The analysis is carried out under the low Reynolds number and long wavelength approximations and the fluid and cilia dynamics is of the creeping type. A Lorentzian magnetic body force model is employed and magnetic induction effects are neglected. Solutions to the transformed boundary value problem are obtained via numerical integration. The influence of cilia length parameter, Hartmann (magnetic) number, heat absorption parameter, Grashof number (free convection), solid nanoparticle volume fraction, and cilia eccentricity parameter on the flow and heat transfer characteristics (including effective thermal conductivity of the nanofluid) are examined in detail. Furthermore a comparative study for different nanoparticle geometries (i.e. bricks, platelets and cylinders) is conducted. The computations show that pressure increases with enhancing the heat absorption, buoyancy force (i.e. Grashof number) and nanoparticle fraction however it reduces with increasing the magnetic field. The computations also reveal that pressure enhancement is a maximum for the platelet nano-particle case compared with the brick and cylinder nanoparticle cases. Furthermore the quantity of trapped streamlines for cylinder type nanoparticles exceeds substantially that computed for brick and platelet nanoparticles, whereas the bolus magnitude (trapped zone) for brick nanoparticles is demonstrably greater than that obtained for cylinder and platelet nanoparticles.The present model is applicable in biological and biomimetic transport phenomena exploiting magnetic nanofluids and ciliated inner tube surfaces

    Variable-viscosity thermal hemodynamic slip flow conveying nanoparticles through a permeable-walled composite stenosed artery

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    This paper presents a mathematical model for simulating viscous, incompressible, steady-state blood flow containing biocompatible copper nanoparticles and coupled heat transfer through a composite stenosed artery with permeable walls. Wall slip hydrodynamic and also thermal buoyancy effects are included. The artery is simulated as an isotropic elastic tube, following Joshi et al (2009), and a variable viscosity formulation is employed for the flowing blood. The equations governing the transport phenomena are non-dimensionalized and the resulting boundary value problem is solved analytically in the steady state subject to physically appropriate boundary conditions. Numerical computations are conducted to quantify the effects of relevant hemodynamic, thermophysical and nanoscale parameters emerging in the model on velocity and temperature profiles, wall shear stress, impedance resistance and also streamline distributions. The model may be applicable to drug fate transport modeling with nanoparticle agents and also the optimized design of nanoscale medical devices for diagnosing stenotic diseases in circulatory systems

    Faktor yang Mempengaruhi Keselarasan Sistem Informasi Akuntansi pada Perusahaan Manufaktur di Indonesia

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    Keberhasilan manajemen Perusahaan manufaktur dalam mengambil sebuah keputusan tergantung dari pengaturan sistem informasi akuntansi yang terintegrasi dengan baik. Perusahaan manufaktur yang terdaftar di Bursa Efek Indonesia (BEI) juga mulai melakukan penyelarasan pada sistem informasi akuntansinya. Agar proses penyelarasan sistem informasi akuntansi dapat berjalan dengan baik, maka harus diperhatikan faktor yang mempengaruhi keselarasan informasi akuntansi tersebut. Penelitian ini bertujuan untuk mengetahui faktor-faktor apa sajayang mempengaruhi keselarasan sistem informasi akuntansi, khususnya di Perusahaan manufaktur. Penelitian ini menggunakan kuesioner yang disebar ke 100 responden, untukmenguji faktor manajemen pengetahuan, penggunaan tenaga ahli eksternal, dan penggunaanahli internal dalam menyelaraskan sistem informasi akuntansi. Uji statistik yang dipakai adalah Uji-t. Berdasarkan hasil uji, ditemukan bahwa pengetahuan manajemen dan penggunaan ahli internal mempengaruhi keselarasan sistem informasi akuntansi Perusahaan manufaktur di Indonesia

    Peristaltic transport of bi-viscosity fluids through a curved tube : a mathematical model for intestinal flow

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    The human intestinal tract is a long curved tube constituting the final section of the digestive system in which nutrients and water are mostly absorbed. Motivated by the dynamics of chyme in the intestine, a mathematical model is developed to simulate the associated transport phenomena via peristaltic transport. Rheology of chyme is modelled using the Nakamura-Sawada bi-viscosity non-Newtonian formulation. The intestinal tract is considered as a curved tube geometric model. Low Reynolds number (creeping hydrodynamics) and long wavelength approximations are taken into consideration.Analytical solutions of the moving boundary value problem are derived for velocity field,pressure gradient and pressure rise. Streamline flow visualization is achieved with Mathematica symbolic software. Peristaltic pumping phenomenon and trapping of the bolus are also examined. The influence of curvature parameter, apparent viscosity coefficient (rheological parameter) and volumetric flow rate on flow characteristics is described. Validation of analytical solutions is achieved with a MAPLE17 numerical quadrature algorithm. The work is relevant to improving understanding of gastric hydrodynamics and provides a benchmark for further computational fluid dynamics (CFD) simulations

    Influenza vaccination for NHS staff: attitudes and uptake.

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    OBJECTIVES: Annual vaccination against influenza (flu) is recommended for all UK National Health Service (NHS) staff to help reduce the risk of contracting the virus and transmitting it to patients. However, despite flu campaigns and vaccination promotion, uptake remains low. The aim of this study was to investigate staff attitudes to flu vaccination to see how this may influence their decision to be vaccinated. METHODS: An online survey was sent to staff members across 6 NHS trusts, asking if staff had been vaccinated in the preceding flu season (2013-2014); the survey included questions about beliefs and attitudes to the vaccination, scored on a 5-point Likert scale. RESULTS: 3059 NHS staff members responded to the survey (86% in the 26-59 age group, 77% female and 84% hospital based). 68% of respondents reported being vaccinated in the preceding year. Using a stepwise regression model, the survey response retained as a positive predictor of having been vaccinated was people working in healthcare should have the flu vaccination every year (p<0.001), and the responses retained as negative predictors were the flu vaccination will make me unwell (p<0.001) and the flu vaccination was too much trouble for me (p<0.001). Analysis by staff group showed a significant difference in the response to the flu vaccination will make me unwell between groups (p=0.01), with doctors having a greater tendency to disagree with this statement than other staff members. CONCLUSIONS: These results suggest that addressing NHS staff beliefs around the need for vaccination, while ensuring that practical barriers to having the vaccination are removed, may help to increase uptake. An emphasis on alleviating the concerns of particular staff groups regarding adverse effects of the vaccine may also be of benefit in improving uptake, to protect patients as well as staff

    Mathematical model for ciliary-induced transport in MHD flow of Cu-H2O nanoĂźuids with magnetic induction

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    Motivated by novel developments in surface-modified, nanoscale, magnetohydrodynamic (MHD) biomedical devices, we study theoretically the ciliary induced transport by metachronal wave propagation in hydromagnetic flow of copper-water nanofluids through a parallel plate channel. Under the physiological constraints, creeping flow is taken into consideration i.e. inertial forces are small compared with viscous forces. The metachronal wavelength is also considered as very large for cilia induced MHD flow. Magnetic Reynolds number is sufficiently large to invoke magnetic induction effects. The physical problem is linearized and exact solutions are developed for the resulting boundary value problem. Closed-form expressions are presented for the stream function, pressure rise, induced magnetic field function and temperature. Mathematica symbolic software is used to compute and illustrate numerical results. The influence of physical parameters on velocity profile, pressure gradient and trapping of bolus are discussed with the aid of graphs. The present computations are applicable to simulations of flow control of in nano-magneto-biomimetic technologies
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