694 research outputs found

    Albumin protein coronas render nanoparticles surface active: consonant interactions at airā€“water and at lipid monolayer interfaces

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    Protein coronas are known to alter the physicochemical properties, colloidal stability, and biological fate of nanoparticles. Using human serum albumin (HSA) and polystyrene nanoparticles (NPs) with anionic or cationic surface chemistries, we show that protein coronas also govern the surface activity of PS nanoparticles as well as their interactions with a model red blood cell (RBC) lipid monolayer. The adsorption kinetics of bare nanoparticles (no corona) and nanoparticles with a hard corona (HC) at an airā€“water interface were well-described theoretically, which revealed that the adsorption energy was greater with the corona due to hydrophobic interactions that were enhanced with protein restructuring. Corona complexation increased the concentration of nanoparticles at the interface and led to the formation of interfacial aggregates. Despite clear differences in monolayer structure, the compressibility of PSā€“HC monolayers was similar to free HSA, indicating that conformational changes associated with the protein were not restricted in a hard corona. The intrinsic behavior of the proteins driving the surface activity and compressibility of the complexes at an airā€“water interface was also observed at an airā€“lipid (RBC)ā€“water interface. In this case the lipid monolayer acted as a barrier and reduced the interface concentration of bare nanoparticles. However, with a corona the nanoparticles penetrated into the monolayer and led to the formation of NPā€“HCā€“lipid ā€˜pillarsā€™ that extended into air. Our results suggest that nanoparticle surface activity, and changes in surface activity due to corona formation, are insightful parameters to predicting nanoparticleā€“membrane interactions, complementing the conventional view that electrostatic forces are dominant

    Solving Ratio-Dependent Predator-Prey System with Constant Effort Harvesting using Variational Iteration Method

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    Due to wide range of interest in use of bio-economic models to gain insight into the scientific management of renewable resources like ļ¬sheries and forestry,variational iteration method (VIM) is employed to approximate the solution of the ratio-dependent predator-prey system with constant eļ¬€ort prey harvesting.The results are compared with the results obtained by Adomian decomposition method and reveal that VIM is very eļ¬€ective and convenient for solving nonlinear differential equations

    Solitary Wave Solutions for a Time-Fraction Generalized Hirota-Satsuma Coupled KdV Equation by a New Analytical Technique

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    A new iterative technique is employed to solve a system of nonlinear fractional partial differential equations. This new approach requires neither Lagrange multiplier like variational iteration method (VIM) nor polynomials like Adomian's decomposition method (ADM) so that can be more easily and effectively established for solving nonlinear fractional differential equations, and will overcome the limitations of these methods. The obtained numerical results show good agreement with those of analytical solutions. The fractional derivatives are described in Caputo sense

    Surface Activity of Poly(ethylene glycol)-Coated Silver Nanoparticles in the Presence of a Lipid Monolayer

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    We have investigated the surface activity of poly(ethylene glycol) (PEG)-coated silver nanoparticles (Ag-PEG) in the presence or absence of lipid monolayers comprised of monounsaturated dioleoylphosphocholine and dioleoylphosphoglycerol (DOPC/DOPG; 1:1 mol ratio). Dynamic measurements of surface pressure demonstrated that Ag-PEG were surface-active at the air/water interface. Surface excess concentrations suggested that at high Ag-PEG subphase concentrations, Ag-PEG assembled as densely packed monolayers in the presence and absence of a lipid monolayer. The presence of a lipid monolayer led to only a slight decrease in the excess surface concentration of Ag-PEG. Surface pressureā€“area isotherms showed that in the absence of lipids Ag-PEG increased the surface pressure up to 45 mN mā€“1 upon compression before the Ag-PEG surface layer collapsed. Our results suggest that surface activity of Ag-PEG was due to hydrophobic interactions imparted by a combination of the amphiphilic polymer coating and the hydrophobic dodecanethiol ligands bound to the Ag-PEG surface. With lipid present, Ag-PEG + lipid surface pressureā€“area (Ļ€ā€“A) isotherms reflected Ag-PEG incorporation within the lipid monolayers. At high Ag-PEG concentrations, the Ļ€ā€“A isotherms of the Ag-PEG + lipid films closely resembled that of Ag-PEG alone with a minimal contribution from the lipids present. Analysis of the subphase silver (Ag) and phosphorus (P) concentrations revealed that most of the adsorbed material remained at the air/lipid/water interface and was not forced into the aqueous subphase upon compression, confirming the presence of a composite Ag-PEG + lipid film. While interactions between ā€œwater-solubleā€ nanoparticles and lipids are often considered to be dominated by electrostatic interactions, these results provide further evidence that the amphiphilic character of a nanoparticle coating can also play a significant role

    Onset of the Mutual Thermal Effects of Solid Body and Nanofluid Flow over a Flat Plate Theoretical Study

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    The falling and settling of solid particles in gases and liquids is a natural phenomenon happens in many industrial processes. This phenomenon has altered pure forced convection to a combination of heat conduction and heat convection in a flow over a plate. In this paper, the coupling of conduction (inside the plate) and forced convection of a non-homogeneous nanofluid flow (over a flat plate) is investigated, which is classified in conjugate heat transfer problems. Two-component four-equation non-homogeneous equilibrium model for convective transport in nanofluids (mixture of water with particles<100nm) has been applied that incorporates the effects of the nanoparticles migration due to the thermophoresis and Brownian motion forces. Employing similarity variables, we have transformed the basic non-dimensional partial differential equations to ordinary differential ones and then solved numerically. Moreover, variation of the heat transfer and concentration rates with thermal resistance of the plate is studied in detail. Setting the lowest dependency of heat transfer rate to the thermal resistance of the plate as a goal, we have shown that for two nanofluids with similar heat transfer characteristics, the one with higher Brownian motion (lower nanoparticle diameter) is desired

    Solving Ratio-Dependent Predator-Prey System with Constant Effort Harvesting Using Homotopy Perturbation Method

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    Due to wide range of interest in use of bioeconomic models to gain insight into the scientific management of renewable resources like fisheries and forestry, homotopy perturbation method is employed to approximate the solution of the ratio-dependent predator-prey system with constant effort prey harvesting. The results are compared with the results obtained by Adomian decomposition method. The results show that, in new model, there are less computations needed in comparison to Adomian decomposition method

    Intermittent Control for Safe Long-Acting Insulin Intensification for Type 2 Diabetes: In-Silico Experiment

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    Around a third of type 2 diabetes patients (T2D) are escalated to basal insulin injections. Basal insulin dose is titrated to achieve a tight glycemic target without undue hypoglycemic risk. In the standard of care (SoC), titration is based on intermittent fasting blood glucose (FBG) measurements. Lack of adherence and the day-to-day variabilities in FBG measurements are limiting factors to the existing insulin titration procedure. We propose an adaptive receding horizon control strategy where a glucose-insulin fasting model is identified and used to predict the optimal basal insulin dose. This algorithm is evaluated in \textit{in-silico} experiments using the new UVA virtual lab (UVlab) and a set of T2D avatars matched to clinical data (NCT01336023). Compared to SoC, we show that this control strategy can achieve the same glucose targets faster (as soon as week 8) and safer (increased hypoglycemia protection and robustness to missing FBG measurements). Specifically, when insulin is titrated daily, a time-in-range (TIR, 70--180 mg/dL) of 71.4Ā±\pm20.0\% can be achieved at week eight and maintained at week 52 (72.6Ā±\pm19.6%) without an increased hypoglycemia risk as measured by time under 70 mg/dL (TBR, week 8: 1.3Ā±\pm1.9% and week 52: 1.2Ā±\pm1.9%), when compared to the SoC (TIR at week 8: 59.3Ā±\pm28.0% and week:52 72.1Ā±\pm22.3%, TBR at week 8: 0.5Ā±\pm1.3% and week 52: 2.8Ā±\pm3.4%). Such an approach can potentially reduce treatment inertia and prescription complexity, resulting in improved glycemic outcomes for T2D using basal insulin injections.Comment: 6 pages, 2 figures, conferenc

    INTEND OF ELEGANT ANTI ROBBERY SYSTEM FOR VEHICLE REFUGE WITH IOT TECHNOLOGY

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    Finger print sensing unit records the finger print pictures, matches the diversity of every print checked out through the sensing unit and also contrasts it to the only kept in its component or neighbourhood tool data source. An auto surveillance gadget that functions making use of GPS and also GSM generation, so one can be the least expensive supply of lorry surveillance and also it could art work as an anti-theft device. It is an ingrained gadget this is utilized for monitoring as well as positioning of any type of vehicle using utilizing Global Positioning System and also global maker for cell interaction. It will constantly show a moving car. This system has single board ingrained tool that is prepared with GPS as well as GSM modems combined with ARM cpu which is connected to the automobile. After pushing the emergency situation type in situation of a trouble, SMS is sent out to the web server using SMS utilizing AT command. The taken cars and truck might be tracked making use of a GPS tracker which is similarly being linked. The certain layers of safety and security specified is managed using making use of an ARM 7 based controller acting due to the appropriate node. The full equipment was analyzed utilizing an examination instalment with the help of resembling the car door, vehicle immobilizer and so forth. With equivalent vehicles while Fingerprint documents come to be gotten from Matlab based completely definitely GUI energy. The speculative impacts confirmed the performance of the anti-robbery gadget in the functioning environments

    Investigation of Transient MHD Couette flow and Heat Transfer of Dusty Fluid with Temperature-Dependent Oroperties

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    In the present study, transient MHD Couette flow and heat transfer of dusty fluid between two parallel plates and the effect of the temperature dependent properties has been investigated. The thermal conductivity and viscosity of the fluid are assumed as linear and exponential functions of temperature, respectively. A constant pressure gradient and an external uniform magnetic field are considered in the main flow direction and perpendicular to the plates, respectively. A hybrid treatment based on finite difference method (FDM) and differential transform method (DTM) is used to solve the coupled flow and heat transfer equations. The effects of the variable properties, Hartman number, Hall current, Reynolds number and suction velocity on the Nusselt number and skin friction factor have been discussed. It is found that when Hartman number increases, skin friction of the upper and lower plates increases
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