19 research outputs found

    Proinflammatory Activation of Osteoclasts Due to High Prolactin Level

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    High concentrations of prolactin (PRL) during the lactation period have an essential role in milk production by mammary glands stimulation. PRL may have an impact on calcium regulation and bone mineral density. We investigated if the PRL concentration during the lactation period could influence osteoclast (OC) activation and bone mineral density (BMD). In vivo, the Calcium Detection Assay, and ELISA were used to detect serum calcium, PRL, and inflammatory cytokines, respectively. BMD was evaluated by µ-CT in six months old female mice during lactation. The osteoclast (OC) activity was detected by Tartrate-resistant acid phosphatase (TRAP), Immunohistochemistry (IHC), and hematoxylin and eosin (H&E). In vitro, osteoclast differentiation, resorption and their activity markers TRAP, Matrix metallopeptidase 9 (MMP-9), Cathepsin K (CTSK), C-reactive protein (CRP), Receptor activator of nuclear factor kappa-Β (RANK) and inflammatory cytokines were measured in osteoclasts stimulated with recombinant prolactin protein (rPRL) or with an anti-prolactin blocker. We found that serum calcium, PRL, and inflammatory markers were increased. BMD was significantly reduced in lactating mice; TRAP activity was increased and tubercular was reduced in lactating mice compared to normal mice. In vitro, the osteoclast number, resorption, and activation markers TRAP, MMP-9, CTSK, CRP, and RANK were significantly increased after treatment with rPRL protein, but not in osteoclasts treated with anti-prolactin receptor antibody and rPRL. The gene expression of TNF-α, IL-6, and Monocyte chemoattractant protein-1 (MCP-1) but not IL-1b were significantly increased in osteoclasts with PRL treatment compared to the untreated osteoclasts. Taken together, the high level of PRL could activate osteoclasts and proinflammatory cytokines expression which reduce BMD in the lactation period

    Investigation of two phase unsteady nanofluid flow and heat transfer between moving parallel plates in the presence of the magnetic field using GM

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    In this paper, unsteady two phase simulation of nanofluid flow and heat transfer between moving parallel plates, in presence of the magnetic field is studied. The significant effects of thermophoresis and Brownian motion have been contained in the model of nanofluid flow. The three governing equations are solved simultaneously via Galerkin method. Comparison with other works indicates that this method is very  applicable to solve these problems. The semi analytical analysis is accomplished for different governing parameters in the equations e.g. the squeeze number, Eckert number and Hartmann number. The results showed that skin friction coefficient value increases with increasing Hartmann number and squeeze number in a constant Reynolds number. Also, it is shown that the Nusselt number is an incrementing function of Hartmann number while Eckert number is a reducing function of squeeze number. This type of results can help the engineers to make better and researchers to investigate faster and easier

    Two-Dimensional Variable Property Conjugate Heat Transfer Simulation of Nanofluids in Microchannels

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    Laminar two-dimensional forced convective heat transfer of CuO-water and Al2O3-water nanofluids in a horizontal microchannel has been studied numerically, considering axial conduction effects in both solid and liquid regions and variable thermal conductivity and dynamic viscosity. The results show that using nanoparticles with higher thermal conductivities will intensify enhancement of heat transfer characteristics and slightly increases shear stress on the wall. The obtained results show more steep changes in Nusselt number for lower diameters and also higher values of Nusselt number by decreasing the diameter of nanoparticles. Also, by utilizing conduction number as the criterion, it was concluded from the results that adding nanoparticles will intensify the axial conduction effect in the geometry considered

    Nonlinear algorithm of PEM fuel cell catalyst poisoning progress in the presence of carbon monoxide in anode fuel: A computational study using OpenFOAM

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    This paper presents a model to theoretically study the key poisoning-related concepts including Dimensionless Cell Voltage (DCV), nonlinear algorithm of poisoning progress, smooth and accelerated poisoning progress regions, intensification point, and the rate of poisoning progress. A 3-D multicomponent transient solver, based on a comprehensive mathematical model including reaction kinetics, governing equations, boundary conditions and constitutive relations, in the open source code package, OpenFOAM, has been developed that has the capability of simulating anode side of PEM fuel cell in poisoning condition. This study suggests an optimum parametric voltage range for choosing purge characteristics of fuel cells operated in dead ended mode as well as an optimum range of efficient oxygen bleeding that must be used to cure or prevent CO poisoning. Studying the effects of key operating conditions on the poisoning progress algorithm showed that increasing the CO concentration, current density and operating temperature, and also lowering the catalyst Pt loading can all reduce the poisoning period and speed up its progress rate. The results also showed that poisoning progress follows a nonlinear algorithm. Based on the Response Surface Method (RSM), a series of parametric correlations were extracted to predict the poisoning progress algorithm according to above-mentioned operating conditions

    Investigation of blood flow rheology using second-grade viscoelastic model (Phan-Thien–Tanner) within carotid artery

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    Purpose: Hemodynamic factors, such as Wall Shear Stress (WSS), play a substantial role in arterial diseases. In the larger arteries, such as the carotid artery, interaction between the vessel wall and blood flow affects the distribution of hemodynamic factors. The fluid is considered to be non-Newtonian, whose flow is governed by the equation of a second-grade viscoelastic fluid and the effects of viscoelastic on blood flow in carotid artery is investigated. Methods: Pulsatile flow studies were carried out in a 3D model of carotid artery. The governing equations were solved using finite volume C++ based on open source code, OpenFOAM. To describe blood flow, conservation of mass and momentum, a constitutive relation of simplified Phan-Thien–Tanner (sPTT), and appropriate relations were used to explain shear thinning behavior. Results: The first recirculation was observed at t = 0.2 s, in deceleration phase. In the acceleration phase from t = 0.3 s to t = 0.5 s, vortex and recirculation sizes in bulb regions in both ECA and ICA gradually increased. As is observed in the line graphs based on extracted data from ICA, at t = 0.2 s, τyy is the maximum amount of wall shear stress and τxy the minimum one. The maximum shear stress occurred in the inner side of the main branch (inner side of ICA and ECA) because the velocity of blood flow in the inner side of the bulb region was maximum due to the created recirculation zone in the opposite side in this area. Conclusions: The rheology of blood flow and shear stress in various important parts (the area that are in higher rates of WSS such as bifurcation region and the regions after bulb areas in both branches, Line1–4 in Fig. 7) were also analyzed. The investigation of velocity stream line, velocity profile and shear stress in various sections of carotid artery showed that the maximum shear stress occurred in acceleration phase and in the bifurcation region between ECA and ICA which is due to velocity gradients and changes in thinning behavior of blood and increasing strain rate in Newtonian stress part

    Application of level-set method in simulation of normal and cancer cells deformability within a microfluidic device.

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    Application of microfluidic systems for the study of cellular behaviors has been a flourishing area of research in the past decade. In the process of probing cell biomechanics the passage of a cell through a narrow microchannel or a small pore has attracted much attention during the recent years. And the study of cellular deformability and transportability using these systems with enhanced resolution and accuracy has opened a new paradigm for high-throughput characterization of both healthy and diseased cell populations.Here we use the level-set method to explore the relationship between the transit time and mechanical properties of normal white blood cells (WBCs) and breast cancer epithelial cells (MCF7) under different microenvironmental parameters (i.e., pressure difference, cell size, effective cell surface tension, constriction size and taper angle) in a 2-D computational domain by considering the cell as a viscous drop. The novel biomechanical relations are obtained for each cell type by the Response Surface Method (RSM), relating microenvironmental parameters to the dimensionless entry time of the normal and cancer cells. Our results revealed that MCF7 cells show asignificantly different behavior (a bifurcating behavior when the pressure difference of inlet/outlet increases) in regards to the dimensionless entry time as a function of microchannel taper angle in comparison with the WBC. These results suggest that the microenvironmental parameters have a significant effect on the transportability of the cells and different cells have different behaviors in response to a specific microenvironmental parameter. Finally, it can be claimed that this method can be also utilized to distinguish between benign and cancerous cells or even to probe tumor heterogeneity toward high throughput cell cytometry

    Autosomal dominant hereditary macrothrombocytopenia in an Iranian family

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    Objective: Thrombocytopenia is the most common hemostatic disease of the newborn. Inherited giant platelet syndromes are a heterogeneous group of rare bleeding disorders. In this paper we describe here a female neonate with autosomal dominant hereditary macrothrombocytopenia. Case report: A female neonate was referred to our center due to mucosal hemorrhage (nasal and gastrointestinal bleeding). Her mother's platelet count was normal. However her father, paternal uncle and two paternal aunts also had severe thrombocytopenia and all of them underwent splenectomy for idiopathic thrombocytopenic purpura (ITP). Considering all clinical and laboratory findings, autosomal dominant hereditary macrothrombocytopenia was the best diagnosis. Conclusion: It is important to differentiate between congenital and acquired thrombocytopenia to avoid unneeded and potentially harmful therapy. Treatment is not usually necessary, however some patients with hereditary thrombocytopenia may benefit from bone marrow transplantation

    Heat transfer optimization of two phase modeling of nanofluid in a sinusoidal wavy channel using Artificial Bee Colony technique

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    The present study represents the heat transfer optimization of two-dimensional incompressible laminar flow of Al2O3-water nanofluids in a duct with uniform temperature corrugated walls. A two phase model is applied to investigate different governing parameters, namely: Reynolds number (100 ≤ Re ≤ 1000), nonofluids volume fraction (0% ≤ ϕ ≤ 5%) and amplitude of the wavy wall (0 ≤ α ≤ 0.04 m). For optimization process, a recent spot-lighted method, called Artificial Bee Colony (ABC) algorithm, is applied, and the results are shown to be in a good accuracy in comparison with another well-known heuristic method, i.e. particle swarm optimization (PSO). The results indicate that the effect of utilizing nanoparticles and increasing Reynolds number is more intensified on growing the average Nusselt number than variations of the amplitude of the wavy wall. To prevent the worst possible heat transfer, the specific amplitude which leads to a minimum average Nusselt number is detected. The effect of using nanoparticles on thermal-hydraulic performance factor (j/f) is presented which considers both heat transfer and hydrodynamics aspects. The results showed that volume fraction has a direct and the wavy wall's amplitude has a converse effect on the thermal-hydraulic performance factor. Furthermore, an optimum value for Reynolds number is found to maximize the thermal-hydraulic performance factor
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